Wel, the best way would be to use one of the many flexible joints and/or right angle screw drivers that almost always can get to a screw or bolt. Depening upon the amoutn of access you have, you could always use an mototool and a cutting wheel to carefully cut through the clamp, making sure you did not cut into the mouting surface, but you really should not have to do this if you use some ingenuity and the right angle screwdriver or flexible socket on the clamp.
P.S. In the worst case, you can always use a hacksaw blade, with some tape wrapped around one end as a handle, to cut it off. It take patience and, as I said, you must be careful not to cut anything other than the clamp and the hose.
P.S. In the worst case, you can always use a hacksaw blade, with some tape wrapped around one end as a handle, to cut it off. It take patience and, as I said, you must be careful not to cut anything other than the clamp and the hose.