My Panasonic Microwave was really easy to fix. On the bottom there's a metal panel that is almost punched out. It's hanging on by a couple of metal tags that can be cut with side cutters (wire cutters if you like) Simply snip these on three sides and bend back the panel to reveal the turntable motor. Take out the couple of screws holding the motor and it falls out. Replacement motor costs less than £10.
I just taped the metal cover back down with some aluminium duct tape. You could use large (short) self tapping screws to do the same.