[triton]

you have to use a a/c line quick connect tool. You can either go borrow the size you need or buy the set from NAPA or some place. They aren't expensive. I would replace the lines with new ones from the dealer. The all aren't very expensive.... about $50 for both

 

[emwrench]

Return the junkyard cooler and buy a new one. You could be contaminating your fluid with who-knows-what from that old cooler. Flushing a cooler is also a questionable act if you talk to a trans shop. A new cooler is expensive until you compare it to the price of a complete trans rebuild and then a new cooler anyway.