Ford AOD maintenance...?

I have a '91 Lincoln Mark VII, and the trans slips in first gear. I don't think it's a front pump or TC, all the other gears engage like gangbusters, and pull strongly without slippage. I know it is more than likely worn bands, but I have heard the OE valvebodies on AODs have a habit of getting gunked up, which will prevent sufficient pressure to keep the bands tight. With this in mind, I am going to remove the VB and clean it out before looking at a rebuild. Anything in particular I should be careful of when removing/ cleaning the VB? I don't want to create more problems than I solve, and DIY manuals are no help, as they absolutely refuse to mention anything about auto trannys other than fluid and filter changes. I'm a competent DIY mechanic, just have never owned an automatic car. I'm seriously thinking T-5 swap later on down the road, LOL.