A change of power... battery change info needed

[Matt Agajanian]

Yes, thank you. But, what I'm asking is what are the screwdriver head sizes I need for each model. I cannot judge the diameter I need because they are so small, I end up picking the wrong screwdriver and try it only to find that I've mangled the head because I picked up the wrong size.

Please bear with me because I have no toolkit experience.