i think you may have to prise the handle away from the part that has the cable. the handle may have a plastic section on each side that clips onto the cable housing. in which case you will need a thin screwdriver. the area that the cable is settled in separate from the rest of the handle assemble.
I know you dont need to replace the cable but once the handle assembly is off, the cable section has to be twisted to be removed. as I say I have done it a couple of times, but I cannot remember exactly how it all comes apart