No, this was from under the hood (1989 model year). There is really quite a bit of room to get to the bolt, you just can't see it. I removed the medium size hose from the bottom of the radiator, the one that runs to the expansion tank, and drained all the coolant I could. Looking back, I should have removed the thermostat to bottom-of-the-radiator hose, I could have saved more coolant as the coolant was almost new. I reused it by straining it before putting it back. I removed the top hose, easy to remove, makes much more working room. I did remove the bottom hose from the thermostat housing. The new thermostat APPEARS to have fixed the problem. The one I removed was a wahler, replaced it with one from the MB dealer, no brand name stamped on it.