right to finish this one. This is what i did.
i had to renew the brake fluid so decided to undo the bleed valve on the caliper. Found it released pressure easier just used brake cleaner once finished to tidy it up. put some newspaper on the ground before you start.
Then got a set of grips (5 holes) turned it CLOCKWISE while pushing with my hand to give it some pressure. one side was a little tricky then the other.
TIP: if you use grips when you come near to fully retracting it in mind you dont pinch the rubberdust cover around the piston.