Hey, so ive just started out, trying things in the single player mode, and im having a small problem. I can grab any part of the persons body (in this case Uke), but after that, i have NOOO clue how to take said body part off, or dismember them. Any help would be very much appreciated.

All you have to do is use momentum to help rip the part off. Rotate your chest, use your legs, ect.

Grabbing some one and RIPPING their body parts off is really hard. i cant do it most of the time. but if you sort of punch but use a grab hand it dismembers alot easier.

Well, firstly, one shouldn't count on being able to just grab a bodypart and then
rip it off, since that would require super-toribashian strength. It is possibly to do
it in a few rare cases, but don't count on it in general.
Instead, one should strike Uke with a lot of force, preferrably directly on the joint.
It may seem a bit hard to do at first, but then you can just use grabby hands
to make your hands hit with the maximum amount of energy.
Also, use many joints. If you are to do a punch from the side, contracting your
left pec and your left elbow isn't going to give a good blow. Instead, one should
like, contract the other pec as well, rotate the chest with the blow etc.
Practice makes perfect! :P

And if you wanna take uke's arms off, aim for the underside of his shoulders. That's the weak spot of the arm.

Well thanks for the whole aim for the joints thing. Ive got 3 new moves down!!! <333

Also propelling yourself with another body part for another part is good (e.g. Propelling yourself with your arms for a kick)
Another type of popular replays are "Madmans", a series of dismemberments as fast as possible, giving you a satisfying replay.
Here's one :

if u grab say, ukes head, or even an arm or something, and u cant get it off, try punching it at the joint with ur other arm whilst ur holding it. this is usually more successful for me

It is fairly easy to break limbs. Either use your's as a wedge to pry them apart, hit them against their base, or twist them beyond their normal movement range to break them.

By the way, labrat, your gif avatar is annoying.

i dont get how u aim for joints. u cant aim that i know of can some1 help me?