what is the location of the frost plug on a 95 jimmy? took the truck to a mechanic and he wanted 200.00 to replace. I should be able to do this myslef with a little help

I am hoping someone can tell me how you remove the fuel filter on this vehicle. One end looks 'easy': use a compression/coupling type fitting type wrench to loosen the nut but the other end looks like some kind of squeeze- push-pull- pinch-twist- tug and whistle Hard Day's Night backwards to release it. I am guessing it comes apart easily if you know what to do with it, and probably have some sort of tool ? I just dont want to mess with it and break it because the end of interest here is part of a several foot long line that looks like it would cost a few bucks to replace if you screw up the business end. But, looking at a new filter and the old one (on the frame rail under the truck) I can not for the life of me see what you do to get it apart. Can anyone help ? Thanks.