hi everyone, i dont normally write in but wandered if you need a special tool to push back the piston in the brake caliper when fitting new pads on the rear. They desperately need doing soon, any advice would be most helpfull

Yes a piston windback tool is normally used.

If its anything like the Octy 1 Diesel its a pig, allow plenty of time, I was assisted by a very knowledgable briskodean & it ended up with a lot of help from a long handled wooden thing with a steel lump on the end, getting the old pads past the lip on the disk was the biggest pain