Use a Phillips #0 screwdriver.

The cover pulls off without much resistance.

Peel the battery up carefully. The adhesive is sticky and lifts easily off the PCB. I was a bit worried about being able to put the battery back, but the adhesive is sufficiently sticky to re-install it.

Four screws are near the middle of the PCB while two screws are hidden away near the motors.

Insert wisdom here.

The covers each have little inserts that can be pulled through with tweezers or pliers when re-installing them.

Insert wisdom here.

Insert wisdom here.

I put the controller back together and it still works!