do I need an electrician? If not which trade?

check with the company that you pay your electricity bills to as they may charge for you

The easiest way usually is to fit an external box cover over the existing box, something like this here: https://www.repairmymeterbox.com/shop/plastic-overboxes/plastic-overbox-for-gas-or-electricity-meter-boxes/ Anyone can fit that, as it isnt touching the internal cabling. If you do want the old box removing, and a new one fitting, then it is complicated, as you will need to disconnect the supply to thread the cable out of the old and into the new box. The local DNO (old Electric Board) need to do that, and probably will charge for it, as well as needing an electrician to disconnect/connect up the outgoing cables, as the DNO dont normally touch cables past the fuse cutout.

The meter box belongs to the customer so it’s their responsibility. It’s a bit awkward as an electrician could take out the old box and fit the new one but he would have to work around the main incoming supply. Ideally the DNO would disconnect their cable and reconnect when the new box is fitted.

Electrician can replace the meter box,or electricity company.the meter need to be moved carefully before the box can be fitted.

An Electrician would do the job.