The pin is 3/32 x 1/2. They make a slab side punch to install so there is less chance of damaging the lower. Otherwise you will need to take extra precaution when installing so you do not hit the lower. I would recommend getting hollow end starter punchs for all roll pins. They hold the roll pin inside the punch so you dont have to worry about the pin launching into space.
Right or wrong, I lightly buzz one end of the roll pin to bevel and put a drop of oil on it, tap in w brass rod. Tape up side of receiver to not leave a mark.