Finally did it! Oil cost about $130 for 9 gallons. I bought 3 packs of 3 gallons from NAPA auto parts because we don't really have a Walmart where I live (shocking, I know).
To catch the oil, I used one of those Costco crate/boxes that I lined with 2 trash bags and then taped around the edges. I filled that up to about an inch from the top. It was definitely cuttin it close lol. But at least it didn't leak.
The hardest part was getting the oil filter off. I bought the biggest oil filter wrench I could find at NAPA and it was still too small. That thing was not budging by hand either, and I'm a strong guy. Eventually, I just used one of these woodworking clamps:
It compressed the filter in a bit but it didn't leak. After a lot of budging it finally came loose. I refilled the bus per crazycal's
instructions. After adding oil to the filter & actual pan, I went through about 7.5/9 gallons that I purchased.
Thanks for the help everyone!