Stuck brake caliper - Ford Transit

Noticen a burning smell after a long drive. I touched the wheels and found one of them to be very hot. I lifted the van and saw the wheel was pretty stuck. in this video I try to get it unstuck so I can use the van whilst I wait for parts.
There are 2 common reasons for brakes binding:
1. The piston in the caliper is stuck
2. The sliders are stuck and the caliper cant slide, meaning that one of the pads is allways applying pressure on the disk.
In my case it is a combination of both.

[@Twinturbo_]

8:52 you must put silicone grease because it goes in a rubber boot.

[@hosuandreiremus]

Ok, I was not sure what temperature the silicon grease is rated to.