I haven't either US1 - I just put them back together using my internal torque wrench - common sense. I'm a saltwater boater and have never had an issue getting them off every other year (no I don't change every year. I only put about 30 hours a year on the last few years so I don't change EVERY year.

use white lithium grease, on the bolts and the impeller itself, best thing since sliced bread for removal.

ya, had pieces in my oil cooler once...sucked. I always use "Perfect Seal" on most bolts, great stuff...http://www.mercstuff.com/perfectseal.htm

used to change impeller with hanging on engine. i take pump off engine now. can inspect seals and other parts, use either grease or antiseize on surfaces and bolts. easier to reassemble. no twisting of pump housing when mounting to bracket, can pull bolts tight evenly. that prevents breaking new plastic pump housing, put light coat of grease on impeller to prevent burnup on initial startup.