How to get parking brake cables off rear axle??

All you've got to do is remove the drum/shoes, etc and find something round like a piece of pipe or a hex nut that has an ID close to the OD of the hole in the backing plate. [Not sure if it was Mopar but I recall once using a 1/2" nut and opened it slightly with a die grinder.] Slip the home made tool over the end of the cable and slide it up against the tabs you want to compress. Hit the tool with a hammer [or a chisel/hammer if you need a little extension] and the tabs will go in. Then all you have to do is tap the end of the cable and it will pop right out of the backing plate.