Impossible to answer without the year and model Oldsmobile you're referring to.
How do I take the back panel off
Hand signal: put your arm straight out of your left hand window and fix the light before a cop sees it
I wouldn't.
all the slinding rear windows that i put in you had to replace the whole rear glass
Put the gasket on the new window. Put a small diameter rope or cord in the channel with a foot or two extra to pull on later. Put window in the opening on the outside of car. Have someone hold window firmly in place. Pull on the cord from inside the car and work the gasket into place. It helps to put powder or wd-40 on gasket to make it slip into place easier.
Front reservoir also serves the rear
where the real tag would go
Try this simple fix. Put the window down then put it all the way back up. Over time and a few bounces the rear window settles down just a bit and this triggers a safety that prevents the defroster from running with the window down, only it's not down enough for you to notice it.
The rear window wiper fluid comes from the windshield wiper fluid tank in the engine compartment on a 2001 Ford Escape
You have to remove the door panel and attach the new window to the window frame this is very easy but it is time consuming and make sure you have no air leaks before you put the door panel back on
Basically you have to put plus and minus 12 volts to the purple and green wire for the left rear or purple/white and lime wire for the right rear window. That is - assuming the wires are disconnected from the driver door switches. Reversing the plus and minus on a set of colors reverses the motor direction for up or down. 2 Worse case you have to remove the door panel to get to the wires at the motor and if 12 volts won't operate it there then it's a bad motor. 3. Remove the motor and wind the window back up (you may have to hold it up )then put the motor back in.
There is only one washer fluid reservoir to supply both front and rear windows.