Removed top cowl; opened up and centered bottom corner grommet holes with files and unibit to 1/2". Secured top cowl to fuselage and bottom cowl; adjusted corner receptacles. Removed cowl and locked receptacle barrels in place. Secure grommets in top cowl with retainer O-rings; experimen with installing top cowl with studs and grommets in place. Less than ideal; removed O-rings and grommets.