you need to buy a little Ford Specific tool from your local auto parts.. unfortunately it makes rear brake pad replacements ALOT easier.. I think its under 12.00 -- it looks like a metal square, it fits into a recess so you turn and get the pads out.
if your unsure as to what your looking for just tell the parts person that your changing your rear brakes on a FORD product and you need a special tool.. they will point you in the correct direction in 2 seconds.