I don't know the mod firsthand, but I'll say just generally not to worry. One of the great things about mechs is being able to completely disassemble/reassemble for cleaning, etc.
As for the actual disassembly, it looks like a standard recessed bottom firing button, so you'll likely just want to remove the button and then break down its assembly. Most commonly the spring is enclosed in a cylinder and held together by the negative contact and the button.
It's smart to know all of your mech's individual parts in the first place, so don't fear and just treat things gently so as to not over torque the parts or strip the threads. Hope this helps.
[EDIT] Videos I'm finding online show a magnetic switch...