You'd have to get at least two gallons of anti freeze just in case cause you're gonna lose some when you drain the radiator. On my D, the t-stat is located on the bottom hose coming from the rad. In my situation, I'd have to get under the engine and disconnect the hose from the t-stat. The t-stat should be held on by two bolts. The recommended replacement would be an 180 degree t-stat. While you're down there why not replace the hose and replace the factory clamps w/ screw-type hose clamps? Wouldn't hurt but would certainly help... Just my .02, HTH.