power window HOW To

Can anyone give me any instructions on replacing the power window motor on a `95 extended cab Silverado. Does everything have to come out of door including window? Also umm we `ve got the door interior trim panel off pulled some screws out of metal panel , took the speaker out but that`s it so far . oh an alarm is now on when the truck is started. I`m guessing it is for door ajar alarm or something like that, Any ideas? ya the door is closed and it stays on and seatbelts are done up . It`s not my truck.
Thanks for any info. Muff