Don't bother with the filter; on the AW4 (not AW5) it's a screen.

Do the drain/fill/drive until fluid stays red. May take 2-3 times.

Use Dex/Merc compatible fluid ONLY, no matter what somebody at the parts counter might try to sell you! Do not use ATF+4. While some AW4 transmissions work okay with it, many do not. Dex/Merc is the spec by Asin Warner, the mfg of the transmission and IMHO, it's the only correct fluid for the AW4.

I second the not bothering with the filter. It is literally a very coarse metal screen. It's not worth the hassle at all. If you wanted to keep it as easy as possible, get something to suck it out from the top and you are golden with no risk to stripping the drain bolt or having a leaking crush washer.

I believe the drain pan bolt is 14 mm and when you drain the pain you will have about 4 quarts to replace.

Seems you are in great hands. Yea I wouldn't bother with the screen. Agreeing with all above. Since it all wont drain you can do your first now, then just repeat with oil changes while you'r there anyway until the fluid looks nice. That's one angle anyway. Myself I went with breaking my cooling line on lord knows what and pumping it all out on the road, emptied within walking distance of home. Ether way works.

I did it all in one go when I bought my 1992 automatic a few years ago. I dropped the pan and changed the filter. I had to unbolted the dip stick tube/fill tube from the block instead of removing it from the pan because the tube was stuck in the pan and I didn't want to break that o-ring seal and leak. I filled the pan from the tube. I had someone start the vehicle with the oil cooler out line going to a bucket while I was pouring into a funnel in the fill tube until the fluid coming out of the oil cooler out line came bright red. I had her kill the engine, then adjusted the fluid level over a couple of weeks of driving. I had to add more fluid than the dip stick shows, but that was likely because the transmission never had been changed and wore from older fluid.

The old filter/screen didn't seem to be dirty. If you are worried about leaks, then don't mess with dropping the pan at all. I did use Dex II?/Merv V?, but all of the manuals state A.T.F.4+ should work. I think that the original specifications fluid was cheaper anyways... So between price and so many on the internet I guess that you should go with the old fluid. Who knows whether it isn't just A.T.F. 4 rebadged anyhow.

All good ^^ info here.

If the gasket is leaking then you could drop the pan. I dropped the pan a couple of times to see what was stuck on the magnet.

Leave it alone if it's not leaking.

A significant concern is that those pan bolts can strip the transmission threads VERY easily. So IMO they either have to be removed periodically and CAREFULLY re-tightened or NEVER touched.

Sorry Dave,but that's not true. It was designed so the plug is softer than the pan and the bolt itself strips.
Replacement bolts with new crush washers can be had at most neighborhood parts stores.

Yeah, I never did find anything.

No, the transmission threads themselves not the plug.