You can also reach that recessed screw by using a flat blade scredriver
bit.  (You know, the one that fits into an electical drill.)  The bit can
easily be turned by fitting a small open end wrench onto the hex shaft of
the bit.  If you don't have the correct size wrench, you can always use a
small adjustable wrench, or even a pliers if you are the sledge hammer type
of mechanic.

It is easier than it sounds, but be careful to not lose the inner spring if
you loosen the screw and it pops out on you.

Budd Premack
86 Syncro, 73 Super
Minneapolis, MN (Land of Sky-Blue Waters)