are you talking about the actual creep as the sear moves on the hammer or the pretravel of the trigger before it contacts the sear?

to convert to SA only..requires new trigger and remove the disconnector ( L-shaped part connected to the hammer)
FPB block will still work.
the SA trigger may or may not be drop in..have seen both..some require some fitting for the trigger bar to work correctly. as said above..a new hammer will require the safety and sear be fitted also.
if you are talking about the creep of the sear moving on the hammer..the hammer hooks will need to be recut to eliminate that creep..or install a new comp hammer..which will require the sear/safety be refitted.
To install new trigger..you will need to disassemble the gun in its entirety..removing the ejector housing, trigger/trigger bar. think there is a step by step in the gunsmithing FAQ