Removing Windshield Wiper arm from Shaft

I am trying figure out how to remove Windshield wiper arm from the shaft My driver side wiper broke loose from the linkage the arm is still attached to the shaft and I can't remove the arm from the shaft. The wiper arm looks like it is press fit on the shaft. I am wondering if I will have to replace the whole linkage assembly but I can't get the passenger side wiper arm off the shaft to remove the leaf guard assembly.

On my '96 I raise the flap covering the attaching nut. Loosen the nut until the shaft threads no longer show. Tap the nut with a rubber mallet while lifting on the arm. Usually pops loose with the first tap.

I saw in the repair manual how to remove by the method you mentioned but my wiper arm is pressed fit on a spline held in by a sliding clip whacked the heck out of it with a small hammer but it didn't budge so i took a hack saw accross the top split it open and finally removed it with a screwdriver without damaging the spline or shaft ...........

Thanks for the response