Go to an auto parts store and get a filter kit. The kit has filter, and pan gasket. Some come with gasket folded, unfold, put in sun 1/2 hour to flatten. Always replace gasket, used one may look OK, but is probably cooked.
Have several large pans handy, as aprox 1 gal will come out. Loosen bolts a little at a time until fluid leaks out. This gets messy, have pans handy. Once pan is off, clean throughly, the bottom will have a metallic mess, that's normal. Brake cleaner, and paper towels make short work of cleanup.
Carefully scrape away old gasket, put some contact cement on pan, and glue new gasket into place, while glue dries, pour oil into jugs, and change filter Bolt up cleaned / re-gasketed pan, tighten bolts gently, and evenly.