i recently replaced my radiator in my 02' chevy xtreme. i got a tranny line removal tool from autozone. if you have problems you can remove the fitting, but replace gasket. the tool takes a little work so be patient.it goes over the line and fits at the connection and rotate it too release the retaining spring/clip. you should be able to pull line out. put a pan under as some fluid will come out.
Nick thank u so much for your quick answer. I never used one b4 so i will purchase a 8 pc set, line removal tool online from BrandsPlace.com for $17.66. I was wondering, because I had tried the 19mm flare wrench and the coupling would not even budge!
Nick, I used the line tool that came with the new radiator and it was a breeze, except the line was stubborn to remove after removing the clip so I used a vise grip locked close to the nut and pried out with a flat head screwdriver in a snap. After everything was put back including new water pump, the car was still overheating with whit smoke coming from tailpipe! Yep looks like a cracked head or block! back to work looking for engine now!