A lot depends on the condition of the rubber. If it is old & scabby, with cracks & lots of oxidation, then i suggest cutting the rubber to ensure the survival of the glass, as it may have hardened too much to get the glass out safely, then use a new seal.

Is it nice & pliable? then it might prove to be ecenomic to use a professional. He should be able to remove it without damaging the seal, & you could re-use it after painting, or whatever.