The first question I have to ask is how much wxperiance do youhave with replacing window regulators and window lift motors? This is a very dangeruse job to do and you can get hurt very quick ly if you do it wrong as the regulator has a spring in it that can cut off limbs.
I do not mind walking you trough ding this task but have to know how much you know to make sure you do the job safely.
I am always safty minded first but to let you know this is the first time I will remove the lift motor
the vise will work great to be able to replace the motor safely. Do you know how to pull the door panel off? You will also need to pull the window glass out as well. is the window all the way up, down, or inbetween?
this is going to be a slight problem. Can you unplug the window motor and run jumper wires to it and see if the motor will work at all to let the window 1/2 way down? The window glass has to be unbolted from the regulator and the glass removed to get the regulator and motor out so you can replace the motor.