I found a writeup on absolute prelude and it says I have to drain the tranny fluid to change out the cv joint... Am I supposed to do this even if I have an automatic? I thought you were only supposed to drain/refill/change an automatics fluid with the machine that pumps it in and out at the same time? Am I mistaken? Or am I ok with draining it and refilling it myself? And where do I refill the fluid? Through the dipstick reservoir? Thanks guys!

 

I think all the auto's use 1 piece cv shafts unlike the 5spds with an intermediate shaft on the drivers side.
So yes you need to drain your auto tranny fluid.
These are my f22a1 auto tranny axles. Your Si h23 might have an intermediate shaft on the drivers side so you need to check.

 

I didnt have to drain my fluid when mine were changed.