Take a razor blade and carefully pry off the thermal sensor diode.
Mine popped off fairly well on the 2nd one I modded. The first toook more work.
People have run theirs with the sensor broken/cut off, but I think it's best to just pry it off with a razor blade.
Remove the glue, and just put some thermal compound on it when installing the new star.
Have fun, this is a great mod. I use the Khatod stippled 17 mm refelctor. Great flood (but no spot).