I bought the replacement felt drum seal and followed the video on Appliancepartspros. It is very useful, however i would add two pieces of advice:
the old glue can be removed more easily by using acetone. If not readily available, check the nail polish remover of wife/partner. Chances are they have pure acetone for the task.
Very important: the glue dries quickly, maybe 1-3 minutes. And the seal is quite tight in length for the drum. So the seal has to be glued very fast and making sure it is well stretched to cover the whole drum. Better getting an extra pair of hands for the task.
Also it is useful to have someone helping while setting back the front panel.
The dryer is working again and no stains so far...