Why not just change the battery?
A battery change shouldn't require heat guns, special suction/clamp tools, or adhesive-dissolving chemicals.
It also shouldn't require being without your device for an unknown period of time to send it in for service.
I've gotten battery replacements on various iPhones, iPads and Macbooks and it's a pretty straightforward processes.
Which is pretty reasonable. Giving up little bits of a control at a time is how we end up with no control at all.