Here is my routine for an oil change...
Return from weekend trip, which is usually a fast run at 2000-3100 RPMs for an hour to 1.5. This gets the oil good and hot and circulated. I then put the boat on the trailer, flush engine with fresh water, and haul it to it's storage spot, about one hour. So...we have run the engine hot, and let it cool down somewhat so not to be a burn hazard.
I then drain the oil from the drain hose attached to the pan. I use a drill pump and put it in a 3 gallon jug. The oil filters will generally drain themselves immediately once the engine is shut down. Back the filters off carefully, allowing any remaining oil to drain. Sometimes there is oil remaining. You can get the filters off empty, and not spill one drop! Remember which is which, bypass and main. Put a little oil on the gaskets of the new filters. Use a sharpie marker to write the date and engine hours on the bottom of the filters. Install them hand-tight only. Refill engine with 3 gal and one quart of oil. I use Delo from Costco where it is about $31 for 3 gallons. Check the oil - it may read high because the filters are still dry.
I don't run the engine again until the next use. I generally need to add another quart (total 3 gal 2 qt) as the filter will absorb some oil. These engines seem to read inconsistently on the dipstick, so be careful about adding too much oil.
Materials - You will need both oil filters and some oil, a drain jug, rubber gloves, and an oil diaper. I rigged up fittings so my drain hose attaches to a drill pump, which has a discharge hose. Part of the job is to be prepared for a colossal mess, then nothing will go wrong. This will be one of the easiest oil changes you will do on any machine.
NOTE - my trusted technician says Volvo Penta is now advising to change the crankcase breather at 100-hour intervals. I would do this at the oil change unless you have that item tracked on another interval.
OPTIONAL - during the middle of the drain, fill a sample bottle from Blackstone Laboratories. I do analysis every 100 hours with the oil/filters change.
OPTIONAL - check the anodes, if you have them, in the charge air cooler and heat exchanger. Once you find the right wrench and figure out where to wiggle your hands into position, it's a quick job. They will waste at different rates so they need to be checked. You may also free some debris from the respective coolers once you pull the anodes, which is a bonus.
OPTIONAL - check the other fluids, such as compressed oil, while you are in there.
I will PM my phone number. Please call to discuss if you wish, and this weekend is fine.