Four years ago I replaced the engine mounts under my 3HM35F engine. The bolt in the forward port mount had broken, we were cruising, and I was away from my more serious tools. A mechanic did most of the work; I was a watcher and helper. The new mounts were Yanmar. We separated the engine coupling and lifted the engine with a PortaPower hydraulic jack placed under the oil pan. We took the opportunity to replace the lag screws into the engine beds with new stainless screws. The re-alignment was not difficult although up/down errors were easier to correct than side to side errors especially with the relatively flexible mounts.