1999 clk320 duo valve replacement question
 

This seems like it should be a piece of cake but I'm stumped and my knuckles are scraped. Can anyone advise how to remove the two rear hose clamps - the screw heads are 6mm and also slotted, but the way the factory angled them makes screwdriver access and wrench access seem impossible. On the oem part in the car, I have already removed the rubber mounts (they slide out of the semi-circular holes) holding the valve in place. Do these clamps get more accessible once the hot water hose from the overflow tank is unfastened? Thanks.