Successfully completed the battery replacement. The removal of the screen was the hardest part. I damaged the gasket like so many here have. I’d like a better description of how to open the unit up without damaging the gasket “if possible”.

Get a de-soldering braid. Remover to add a little flux to the brass before. It will help to suck up the excess solder.

Also, the soldering technique makes a big difference. The smaller the solder gauge and soldering iron tip the better. Use a flux pen/marker to prepare the soldering points on the board. Also add a tiny bit of solder to the top of the ribbon cable points (again apply flux) and it should make the job easier.

Good luck.