they're called [felt] window channels - the top and back are one piece with a flexible metal core, just rip it all out, the front [on division bar] you have to cut/scrape out the felt and glue in replacement felt, or get a new division bar with the rigid metal channel factory finished -
see here near the bottomalso, if yours is original there will be small clips that stab into the channel backside to hold it tight, do not lose those, they're not available repro
Bill