Razor blade or scraper. I saw a trick on television one time. The
painter should put vaseline on the track to keep the paint from adhering
the frame to the moving window.
Of course the right thing to do is take out the moving window and paint
with a fast curing paint. Normally paint drys to the touch but doesn't
cure for up to 30 days.
There comes a time in the affairs of man when he must take the bull by
the tail and face the situation. -- WCF