What is the easiest way to remove the back windscreen

Tape it with a masking tape and from the inside push it out-be careful glasses will be all over-take your time-

Remove the outer moulding first and cut the sealant to remove the glass. Usually a piano string is used to saw the sealants as they can be rather difficult to get at with a blade. You would need somebody to help you to saw the piano string, attached to a wooden bar on either end.

This is a delicate job and requires extra care.

Or a guitar string get a helper one inside the other outside