I am in the process of trying to remove the vent window assemblies on my 1967 convertible with power windows. I may have made a serious error by lowering door glass already. The front clip is removed so I don't have a way to put a battery back in. I have read some suggestions that window glass must be lowered to get vent assembly out. I can lift vent assy. up about an inch and then it stops. Is there a way I can power up the window motor so I can remove bolts that hold glass to regulator? Thanks for the help.