Move plug 100mm higher

I’m putting in a new shelving unit and need to cut a hole in the back of the shelving unit so plug is accessible. Problem is, the plug currently lines up with the interior shelf of wall unit. So the job would be, remove plug sockets (there’s 2 in picture, I don’t need the one on the right) then move one plug up 100mm so it doesn’t line up with shelf anymore. Then cut a little rectangular hole in the back of shelving unit so new plug is accessible. As being covered by shelving unit, you do not need to patch up the old plug socket holes.