I tend to open mine up to find out how they work. Having a plastic bag to work in is a good idea, I have strong magnets on the case as I open them, to catch any small washers or springs.etc.
It's a good idea to activate the release as it takes some pressure off any compressed spring inside.
Clean to get rid of grit on the inside of the case and on the moving parts.
A magnifying glass is helpful,too, to look at the sharp edges of the seers, they sometimes get rounded or chipped.