If your trans lines are the screw in type like my 2005 SXT, the nut size was 18mm, open wrench.
The new radiator I ordered has the hose type fittings. The fittings look like they scew in. I haven't had time yet but I want to see if they do unscrew so I can screw in the transmission lines. If not I guess I either have to send it back or cut off the screw in fittings and use a patch hose (not what I want to do)