the use of a stanley knife

Is it possible to remove the rear side windows without damaging the rubbers? If so, how do you do it,
do the windows go inside out, or outside in?
The rubbers look fairly new and are still very flexible, so if possible I want to save them (tight budget).
However, whoever fitted them didn't repair the window frame before fitting. There is now some fairly
harsh remedial action required, including fabrication of the roof gutters which would be better with
the windows out.
Cheers