If I was doing it again, I definitely would have taken the extra time to use a small squeeze bottle with a tip (or a small tube) to inject sealant through the valve stem. I think it would have resulted in less loss of sealant and less drama if those beads did not have to be seated twice.
Overall, the process was much less involved than replacing a head gasket or other home shop processes. I would say it is similar in difficulty to gluing up a table top out of separate boards.