The route finding is pretty obvious almost to the summit ridge. From Bombardment, you'll see a 45 degree gully cutting up Rumble's SW face. This is your route. Slog your way up this endless rock chute, stopping to examine or attempt some of the rowdy V0/V1 boulders along the way. You'll eventually approach an obvious notch to your left, just below the ridge. Walk directly up to it, then take a ledge to your right. This route bypasses some fun but unnecessary 3rd to 4th class scrambling up cliff bands. Gain the ridge and hit all the high points, because who knows if the summit register is in the right place. Bask in the glory of the shimmering ocean to the west and colossal glaciers to the east.
Coming back over Bombardment was the real test. I was totally worked by the second time I came over! And this time I opted to descend the scree further toward Pleasant instead of chop more steps. Good idea. I now know that most people use a far easier and sneakier way around the rock glacier... Next time!