You will need:
One bag of cement. One bathtub. One set of butcher's tools and bone saw (Dremel or stryker saw will help a lot, too). One cannulation kit (with trocar, preferably pencil point). One water-jet aspirator. One scalpel. One 44-gallon drum. One rental or stolen car, one large body of water. One empty house. One slaughterhouse rack or similar (the object used to hold up carcasses by hooks). Hydrogen peroxide, caustic soda and dilute hydrochloric acid
First, prepare your victim. Poison, gunshot, ligature strangulation are all favorites of mine, but hell, it's dealer's choice. You should be wearing a synthetic balaclava that covers your entire face, clear plastic rainjacket or japara, showercaps over your shoes, nitrile gloves - That sorta thing. Wrab the body in a large plastic sheet or tarp, use a heatgun to seal the ends, and use a staplegun to further hold them down. Use a rental car under a fake name to transport the body. We want to move it as quickly as possible post mortem, before lividity and settling is established.
Find your house. Take the body to the bathroom and set up as many air condidioners in the room as possible - We want it colddddd in here. Shut the doors and windows, then slit open one end of your corpse ravioli. Put up with the stench. Hang them on the slaughterer's hook by the feet and put the plug into the bathtub. Hook the trocar into their carotid artery, take the other end of the cannulation tube and run that inline to the water jet aspirator. Plug the aspirator into the bathtub faucet and turn the water on.
By creating a hypotonic environment in the fresh blood (when it is suctioned and mixed with the tap water), the net concentration of water is higher outside the cells the inside. As any highschool biology graduate will tell you, a difference in concentration around a cell membrane will cause the higher concentration to move to the lower. Basically, the water is forced into the blood corpuscles. Boom! The cells lyse and breakdown into a sludge free of solid organic matter that could have been used for DNA testing. Next, empty your 500g container of sodium hydroxide (caustic soda, draino crystals) into the bath. This will probably cause the blood to spit, boil and splash so watch out! You should be wearing a mask, showercap, thick gloves and safety goggles anyway when working with blood to prevent cross-contamination. Stir it all with a glass rod or plastic pole, and once it's all dissolved (should take 15-60 minutes) use hydrochloric acid (bought from the pool store or hardware store) and litmus paper to neutralise the muck, then siphon (I'm sure you all know how to do this) it into plastic water jerry cans. Store them in the freezer, making sure to leave room for expansion of the blood as it freezes.
Bring your body down from the hook and lay them in the bathtub. Using good-quality butcher's knives (nothing electric, mechanised or with fancy bits that might get blood caught in) remove the arms. Do this by finding the soft spot under the back of the shoulder (if you hold up your arms, you'll see a large muscle under your arm at the back and a small inwards curve - that's the spot) stabbing the point of a large, sharp carving knife in hard. Push it in as deep as it will go without punching out the other side and lever sharply towards the edge of the blade while dragging the blade out to slice through the tendons. Do the same on the other side, continuing in the cut. Then you should be able to just pull the ball out of the socket.
The same can be done with the knees, initial cut should be done in the direct centre of the back face. Hips are a little trickier, just find the soft spot on each side to the interior of the hard pelvis bone. Then bring the cut around over the top to the outside like an upside-down U and twist the thigh sharply to dislodge the remaining meat while working a serrated knife in deeper with a sawing action. The thigh should come away easily. Finally, take the cleaver and the carving knife. Use the carver to hold back the skin flap on the neck while you slide the cleaver in the slit in the windpipe you made and position it over the spine. Then use the back of the carving knife, or preferably a deadblow mallet to hammer hard on the cleaver and axe the spine in half. The head can then be cut away with the carving knife by tracing the point around the back of the neck like a lino cutter.
When you've done that, you should have two shins and feet, two thighs, one torso, two arms and one head. On the torso, identify the stomach. Take a long, sharp rod about 10mm in diameter and at least 300mm long (if hollow, even better) and force it through the diaphragm, through the stomach, and into the lungs, puncturing all three. I find it easiest to start about two inches above and two inches to the right of the belly button, puncturing vertical with the instrument held at about fifteen degrees to the plane of the body. Wiggle the rod, make sure there's a nice open hole. Take your parts, wash them thoroughly in the hydrogen peroxide and then use the rest of the H2O2 on EVERYTHING you touched - Burn anything you can, e.g clothes gloves etc. Take everything and put it in the plastic drum. Get this to 'your' car. Along with the bag of cement, jugs of frozen blood and another jerry can of water. Procure a boat, 20 footer or so, fibreglass powered sort of thing or a small fishing boat/trawler. Put everything on the boat and head out for international waters. Once you hit IW, mix the cement into the 44-gallon drum on top of the parts and wrap the blood cans in chains/anchors and dump them. Put a few kilometres between you and them. Sit back with a cigar and wait for the cement to finish curing. Then roll it off the side and head for shore. In the absence of having access to a boat or IW, a deep lake or major river/estury will suffice.
If you were an idiot and didn't wear your gloves, wipe the boat down with isopropyl alcohol/H2O2 and burn the wipes or rags afterwards. Scatter the ashes into the water. If you return the car in pristine condition to wherever you rented/nicked it from, chances are they'll never link it to the murder. Just make sure you've chalked out the license plates or stolen another pair from somebody else when driving the stuff around, and obey all traffic rules.
That should do you - Anything else that needs to be improvised to suit your situation should be common sense.