Just did the oil-filter change on my Powertech 7kw, not to bad about an hour or so and I have a plexi-glass rock shield I had to remove and replace. Mine has 546hrs over 11yrs of use, on the panel it has a remote start/stop-glow plug, hour meter and a couple breakers on it and maintainence intervals.
Didn't have any manuals, just lurked on this and other sites getting an idea of what I had to do on my '98 Spartan Mountain Master chassis.
First pop the front hood, left of your left leg when sitting at the drivers seat.
Next make sure any rock sheilds, muffler straps, ect are undone so the font generator slide is free to slide out about 2-1/2' .Pull the handle (upper left side above generator) and pull out generator.
On the right gen. cover turn the two small knobs counter clockwise to release the cover..then pull cover off. You'll see both fuel filter-left and oil filter right after the cover is off. Right below the oil filter on mine was a petcock (similar to a radiator) to drain the oil. It would be less messy if you attached a hose to the drain pan so the oil is contained in the pan.
Drain the oil -about 3 quarts and close the petcock when done. Put a rag under the oil filter and remove. Coat new filter gasket lightly with oil and install. Through oil level dipstick hole pour in 3 quarts of your favorite oil, then from the remote starter on the generator start it up and run for about 30 seconds. On mine I had to add another 1/2 to 3/4 quart to top her off. Check the raiator overflow level while your in there and any other maint. or clean-up.
Push the slide back in firmly to hear the lock set and button her up!
Go drink a cold one