Hello and wellcome,
Just as a rough guide..and I havent done it myself,but have removed trim bits and had had to buy new clips
Start at the pull handle for the door.
There should be a small cut at the verybottom where you insert the special tool (screwdriver to you n me).
Lift up and remove the cover,should be a screw at the top.
Next should be a blanking circle of plastic somewhere in the recess where your hand goes when opening the door from the inside.
another screw behind that.
4 more screws around the edge of the trim.. 2 on the bottom ,one high up on the door opening edge and another around the top corner closest to the dash.
Theres push clips as well.
Thats the basic idea from a diagram I have and cant reproduce/link due to copyright n forum rules.
Its actually for a meg 3 but covers scenic as well..and yeh I know the wing mirrors on scenic you need to take the door trim off to replace ,meg 3 you dont.