It is the strip attached to the cab.

It sounds like you are referring to the cab windlace - the weather-seal strip that is attached to the cab, inside the door opening

It is slid into the retainer/track (1959 onwards) and is not normally glued in the track (the track was pinched in a few places after the windlace was positioned tightly in the track).

If this is what you are referring to, you will not be able to save it. It can either be pulled/ripped out of the track or cut out (run a razor or knife through the seal, along the track/retainer).

Tim