Reply To: Stuck trumpet mothpiece
Put your bobcat puller on, and put tension on the mouthpiece. Tap on the bobcat using a mallet (soft faced hammer/rawhide mallet) to try to knock it loose. Sometimes the tension and the tap can get it out.
You could also use the proceedure suggested by Christine and if it does come out doing that alone, then freeze/heat then try the tap-out.
Also suggest that you invest in a mouthpiece tool to round-out mouthpiece shanks. I go through the band regularly using the tool and it has reduced the number of stuck mouthpieces.