This is how I have been doing them for years, it may or may not help you. When you take the axle assembly out you usually end up hitting the end of the axle where the nut goes to drive it out of the hub. This will seat the outter joint tight against the retaining clip.

Put the whole assembly in a big vice.
Remove the outer boot completely.
Take a pocket screwdriver and see if that clip moves freely back and forth or if it is bound up by the outer joint pushing against it.
With it clamped up by the shaft itself take a hammer and punch and drift the out joint forward just enough to release that clip. I always drive on the inner knuckle. You will know that the clip is free when you can reach in there with the pocket screwdriver and move it back and forth (left and right) in the little groove that it is retained in.
Now what I do is go in there with a pair of expanding pliers and spread that clip and then take an air hammer with a flat faced bit and put it right on that inner knuckle and give it one big burp and it pops the knuckle forward just far enough to get the clip out of the groove and keep it expanded. Now you can carefully drive it the rest of the way off.

Hope it helps,
Mark