On the lines, take your pick.
You can either fight with the transmission side top line for 1/2 hour then get soaked, or undo the lower line and still get soaked.
OR, you can undo the line on the cooler side and hope and pray it doesn't break the fitting off the cooler

Ideally I would shoot for the line on the cooler. Easier to get to and will show flow a little better in a controlled manner. But there is the risk of it breaking the cooler if it's corroded pretty bad. I have had them go both ways, and it's about a 50/50 chance.
If it didn't go into gear when you bought it, then sounds like it gave its last effort when you moved it.
Could be a trashed torque converter too though if it has been broke for a while (would have been nice to get ALL the information off the bat

).
Either way at this point, tranny is coming out by the look of it so far.
Martin