UPVC Door hinge access

Looks to me like it clips on, gentle exploration with something broad (reduces damage) and thin at the hinge end or look very closely at the centre of the rounded end there might be signs of a clip there.

Are you sure you need to?

I have similar ones and there is a hole in the end for an allen key which adjusts the reach of the hings.

Under a plug on the top is an allen key socket for height and underneath is an eccentric adjustment

no holes, this plate completely covers the adjustment screws, so there must be a nack to removing it,

I'm sure it should slide sideways then hinge back like a flap, but these won't budge!

this

On mine there is a screw on the "back" of the hinge, that you access with the door open through the gap between doorframe and door. The single screw is undone, then the plate can be removed. Simon.