There exists DIY video for this procedure here:
http://infinitihelp.com/diy/gcoupe/projects/infiniti_g35_window_motor_replacement_procedure.htm
Original Answer:
Remove door panel
unplug old motor and remove bolts holding it, if rivets are olding it you may use a nut and bolt but make sure it doesn't interfere with the windows motion.
Be very patient when reinstalling door panel and don't forget to plug in any switches or anything you unplg when reinstalling door panel
Most likely the window motor is failing. Hit the center of the door liner with your fist while pushing the switch to raise the window. This will only work a few times. Replace the motor.
video on how to replace window lift motor on j30
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Yes
when replacing motor what position does the window need to be in?
don't just replace the window motor replace the whole car. get a hybrid or something
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