I bought a set of front/rear rubber boots from 914Rubber for the parking brake cables. In my ignorance, I figured I could stretch them over the caliper clevis end. Not happening. So what is the trick to replacing them? Thought I needed to pull the cable out of the housing, but looking at a diagram, there are 'big' ends on both.
Am I just not stretching the boot enough?

There is NO TRICK. I have tried both 914Rubber and URO. The rubber compound must be too hard and does not NOT STRETCH. The only thing I forgot to try is boiling them to see what will happen. All I can say is you are not alone.

I've used a pair of snap ring pliers to stretch rubber boots

The last set I bought from Porsche were easy to put on. How about liberal amounts of lube? Try glycerine.

Silicone o-ring grease, muscle and patience.

I got mine from 914 Rubber and they were surprisingly strong. I stretched the crap out of them to get them on, and was sure they would tear, but they held up nicely.

That's where I got them, so I'll give it another go sometime when I have a bit more of the third item...

Same for me.

These three did it. Wire brushed the clevis end to get all the crap off, lubed it and the boot up and with judicious stretching got them on.

Based on this, if Mikey ever needs a sideline, he should go into the condom business. Not sure about comfort, but they would certainly stretch to fit and no worries about failures. '914Rubber rubbers'- has a catchy sound to it...

i did this yesterday and boy are they tight, yet somehow stretchy. got them on and look good! I was surprised that 914rubber does not carry the cables but got them from Sierra Madre, they are made in europe, and fit and work perfectly but dont come with the boot for the ends, so glad 914rubber and URO make these.