I've just been to try an adjust my ride height but the platforms are seized.

Has anyone got any tips for getting these moving, I tried heat and got the bottom lock ring to move but the upper ring for adjusting the height was solid.

I've left it for tonight and soaked the treads etc in spray grease .

If they are ally, soak them in vinegar, if they are steel, soak in penetrating oil. Try tapping the collars with a small hammer as you turn them.

You loosened the grub screw?

make sure you raise the car up and take the weight this also makes them easier

Yep everything is loose and car jacked up, I'll need yo try again with a decent spanner.