triggers are very basic seesaw type sears and are rough stampings coupled with overly strong sear springs
I prefer the one piece 1st variant trigger frame if removing the pins to polish sear be warned they're splined at one end to hold them in
last ones I did were installed from the right so tap out from the left but go steady and tap out a fraction to see if splines are visible if not knock out from other side
later frames are easier as they have a cover to access internals but to avoid losing safety ball and spring remove frame from tube before removing
swapping out the sear spring for a lighter one with a guide and adding an over travel screw to the frame really helps as does a wide blade trigger