I just did this. You have to squeeze the two plastic ears together and with the right amount of squeezing and pulling, it'll come off. Mine did, but the plastic guts stayed on the nipple of the radiator. Well, after $17 for new plastic guts, i struggled and struggled with it to go back on. A few people suggested cuttin it and puttin a hose clamp on it since it's a low pressure ATF line. About 75 miles now and no leakage. If you have the connector with metal guts, you'll need to buy a special tool available at almost any auto store. Do a search for transmission lines and read my posts. Good luck.
Adam