well...if the bottom comes hot from the transmission, if you pull the top, it'll spray oil all over the place...I guess that's the worst case.

 

It doesn't spray, but it does pump it out nicely when you start the engine! I suggest have a spare length of tube available to deal with the overflow.
1. Remove the factory hose from the cooler,
2. Install spare hose from cooler to drain to pan,
3. Start engine and pump out for 1 minute,
4. Replace factory hose.

 

I shared this procedure with my GTO buddies and they thought it was nuts to allow the transmission to run itself almost dry. Wait too long to shut off the engine and your tranny may be a toast. Does anyone here have such concerns?

 

I personally wouldnt go that route.

check the cost on a local shop to do it, when I did and you realize how much time its going to take you, you go negative on cost.

my shop charges 70$
my labor time to do it without a lift is much more than that. plus disposal of fluids.