If you are careful, you can stick it back on. Rewind the tape to the end so as only the leader tape is exposed. I have used cotact adhesive successfully. A light smear only, you donot want to contaminate any of the tape with glue. A better way would be to transfer another pressure pad still attached to its clip from an unwanted cassette to this wanted one. Tricky but possible providing the cassette shell is held together with screws and not one that is welded.
Paul
February 2010