Hi..when you buy a new window regulator it doesn't come with a new motor unless required, the motors are expensive! So, what that means is anyone like me who needed new regulators has to fit the old motor to the new regulator..in turn that means it's not too difficult at all..
If you look at it for a few minutes it'll become obvious what you need to do..You should have some little torx type screw bolts that holds the motor to the baseplate, maybe you'll have a new baseplate on the new regulator i can't remember..(careful when refitting those torx bolts, it's easy to overtighten and strip them.
You have a plug in connector for the motor, that's all the wiring.. the remainder of any wiring or fixings you've probably tackled already if you've removed a window regulator before as you say..
It sounds more complicated than it is.. It'll make sense as you look at it, take your time..
Christo