HAD INSTALLED A NEW ROLLER ON CAT D9R WHEN ONE BOLT BROKE.LOOSENED INSIDE BOLTS SLIGHTLY TO ALLOW ROLLER TO TILT DOWN & OUT OF THE WAY TO REMOVEDUTCHMAN. WHEN REMOVING THE LAST OUTER BOLT THE ROLLER FELL MORE THAN EXPECTED CATCHING THE MIDDLE FINGER ON LEFT HAND. THE ROLLER WEIGHS 250 LBS. WAS USING A 3/4"" IMPACT TO LOOSEN BOTTOM ROLLER