Transmission accumulator M.I.A.

Took my 2000 Passport in today because of a puddle in the garage after an oil change. Turns out the accumulator on the tranny was missing. The retainer ring had obviously given way and the complete assembly was MIA. I ordered the parts which consist of the retainer ring, piston cover, piston spring, piston pin, piston and seal. I have a pretty good idea what I need to do to replace these parts but hoped maybe someone may be able to warn me of potential pittfalls and the like...along with any tricks to make refitting easier. There is always a tried and true method. Any help anyone?:runaround:

http://www.automotiveforums.com/vbulletin/showthread.php?t=184133&highlight=leak

I think you may need a special tool