1. First you craft a "cleaver" (you can use bones, copper, gold and diamonds too)
2. Then you kill a mob (animal) with it.
3. You should get a carcass from it
4. Next you craft a hanging rope (recipe found in JEI) and hang it on a ceiling. (make sure there is a hole beneath it.
5. Now hang the mob on the on the rope and you should see a cleaver sign on your crosshair.
6. Get your cleaver and start right clicking it alot of times (it should lose blood)
7. You know when you are finished when it drops its head!
8. For the next step you need a skinning knife. (again recipe found in JEI)
9. Just right click the mob with it and it should lose it's skin.
10. Then you just have to get your cleaver and right click it, now it should drop all of it's meat and organs.
11. Now that you got all of the meat and organs from the animal you can hover over the item in your inventory and press U. This will show the uses of those items.

I hope this helped and thanks for reading.