I do the same every year (2002 Sanger V210, 350 Mag) to save $400-500. Everything you're doing is pretty easy. A couple of hints from doing this for a few years:
- The Walter V-drive suggest that you change the oil after the first 100 hours and then every 500 thereafter. I've changed this twice, but stopped doing it every year due to the 500 hour suggested interval. I couldn't get my oil pump hose down to the bottom of the V-drive unit to get much/any oil out. Instead, I used the square drain plug on the bottom stern/port corner of the drive unit with a shallow plastic drain pan below.
- I have an oil drain hose clipped to the top of my motor for draining. I used to put an oil pump hose down it and pumped the oil out. Now, to be sure to get it all, I pull the hose through the stern bilge drain connect my oil pump straight up to that and pump out the oil. This has the extra benefit of avoiding possible messes by not pumping the oil inside the boat, but outside standing behind it.
That's all I can think of at the moment.