im about to install some sold motor mounts but im having trouble removing the stud that is in the back or the mount, it looks like it is welded in or some sort of bolt, and i need to get it out to install the aluminum one in that has a stud running through it.

 

The stud in the stock motor mounts is not removable. You need to lift the motor up around 3 inches in order to slide the stud out and put the new mounts on.