I'm with mcduck - leave the drain pan where it is.
Reportedly, even Volvo says to leave the pan and screen filter alone.
I do recommend the flush via hose/tube. See the 70/900 FAQ for the exact procedure.

I switched to Mobil 1 ATF last August. No issues. I did a flush as above.

Since the switch, I've been changing out slightly less than 2.5 qt of tranny fluid at each oil change. I drain the pan via the plug and top it off. Since I change synthetic engine oil at 4-6 K mi. intervals that means I get a full tranny 'flush' every 40 K miles or so. My theory is that I always have about the same percentage of 'young' fluid in there, which is better than a tranny full of old fluid before changing it if you go the regular route. I like it because I can stomach the cost of 2-3 bottles of fluid but the cost of 12-16 qt of synthetic at $6.xx is a lot all at once.
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Sven: '89 245 NA, 951 ECU, expanded air dam, forward belly pan reaches oem belly pan, airbox heater upgraded, E-fan, 205/65-15 at 50 psi, IPD sways, no a/c-p/s belt, E-Codes, amber front corner reflectors, aero front face, quad horns, tach, small clock.