You don't have to melt through that adhesive - it's incredibly weak and you can just pop it out with a sufficiently thin pry bar. This guide [1] does it with an iSesamo, but I just used a utility knife since I had one on hand and wasn't particularly concerned with scratches (the entire seam is covered by the headphone pads, so scratches around it are invisible).

[1]: https://docs.kenp.io/airpods-max/usb-c-kit/v1dot1_assembly/