Can anyone give me an idiots guide to removeng the cover over the 48 pin plug without forcing it please?

 

I have taken mine off before, the socket is held on by a lever which is part of the assembly. Opening the lever loosens the socket, I am afraid that is all I remember. Maybe the method is in the Service Manual.
Forcing it will wreck everything.

 

It’s 2 small tabs on either side of the connector lever, lift at least on side off the locking tabs then pull up on the lever and it’ll disconnect itself. Re connecting is in the reverse order, make sure to leave the lever up when first connecting it other wise it won’t actually connect properly and throw codes.

 

See if this makes sense to you: lift up on top part while twisting a screw driver blade between the edges to force connector open. The outer cover can be removed first by pulling it at the top.The cover snaps into the "handle" of the connector which you will pull up once the cover is off.