On the lower side hose feeding the radiator, on the block side of the hose. 1 clamp, pull it loose, and remember the orientation of the old tstat.. You can make it to the parts store without it, or just do the surgery in the HiLo parking lot - if it takes you more than 5 minutes you're doing something wrong.
This might be a good time to do a nice rad flush, while you're at it, but not in the parking lot.
This might be a good time to do a nice rad flush, while you're at it, but not in the parking lot.