Remove the brass 510 thread with a screwdriver and a delrin washer should come out, you might have to tap it to get it to fall out
Turn it over and pull the bottom pin out with some pliers, then push the top pin out from the bottom through the hole where the bottom pin was with a small screwdriver or something
use a dremel and remove some of the delrin from around the top pin hole, effectively your counter sinking to allow for the top pin head, that's what I did but a proper counter sink bit in a drill will probably work, just don't over do it
Get the delrin washer and enlarge the hole big enough so the 510 of a atty will fit through it
Then just re assemble
That's pretty much it
Don't hold me responsible if it goes wrong bud, that's just how I did it