Need to remove the caliper from the car really as a bench and vice come in handy and working under a wheel arch outside in the rain isn't the best.
Caliper on the bench with the return spring removed, a little care needs to be taken as the spring it under a bit of tension.
Looking at the dirt bild up between the handbrake lever and the caliper body.
I used loads of 3in1 with a bit of white sprits to thin it down and worked the leaver back and forward untill my hands were sore. Then a large screwdriver between the lever and body and with a wiggle, twist and a bit of levering it will come away from the body.
Leaving this. I, like John, couldn't get the lever all the way out. (on either caliper)
Looking down and the dirt / rust build up is thick.