Your tranny doesn't have a "filter" per say. It has a metal screen that you can clean out and reinstall. Some manuals will tell you it has a filter, but it does not.

With that said, I would just do a drain and fill. Remove the drain plug, put a container under it to measure how much you took out, and put back in what you took out. Will be probably 3-4 quarts at the most. You can do this a few times over a period of time and call it good.

Not 100 sure on what ATF to use. What does the dipstick say? Thats what I'd use.

88 4R, 350 V8, R150 5 speed Sold <...uot; />
97 4R, stock, daily driver
98 Sienna, kid and dog hauler, wife's ride