Drill holes like lee said ...you can do it with motor together ...3.00 cobalt drill...slow speed on drill press !!!...it will smoke half way through if you don't have constant cutting fluid...if you "work harden" you will have too dremel with diamond bit (harbor freight) do it all time just takes a little finesse...once you get through dress up inside of rod/oil hole with ball bit you get in the diamond set 3.00 onsale...you cannot use a old wrist pin with new bearing or vice versa...Elliot is correct about the quality of wrist pin bearings... Crap!!! I am lucky enough to have a stash of old SACHs german one's but im runnin low...Got a few og derbi ones too (awsome)...Good luck...ooh almost forgot along with holes in piston boss ...look at a brand new A55 piston with parallel oil slots carved in it ...I do that to every piston