I installed a 10403 on a field stock and can really tell a difference.
One thing I did to remove and reuse oem screws was to take a ball point pen and unscrew the top
and push on the pointed end of the screw. This will protect point of screw.
Also put enough lube of some kind on screwdriver so inside and hole has lube.
I backed out screws until buttpad came off, then put pen top in end with pressure and pressed out screws.
I used smaller wiha philips that has small shaft(PH2 X 100). Hope that helps.