Pull it out. And trim off any that won't pull out.
But first have a look at the two sockets on the back of the box that connect to the left and right centre pipes. Likely the pipe joins are rusted through and maybe also the back of the box. If so you need a new back box and probably the centre silencers.
Be aware that saloon and estate exhausts are different. And 2.2s have two centre boxes unlike the 2.0.
Exhausts at reasonable prices are a bit thin on the ground at the moment. Seems the German and Polish sellers are reluctant to ship to the UK.
You could try here. The exhausts are made by Polmo (Polmostrow in Poland) and are of reasonable quality. Same as supplied by Eternal Car. I'd buy it. However I'm not sure how the customs clearance will work out, you might have to pay a clearance fee and VAT. Some things seem to go through with no customs charges and some get charged.
I suspect that another forum member recently
bought one of these, but I can't find the thread. I've no idea if they're any good. But it's in the UK.
Watch out with the centre boxes. Some suppliers have taken to cutting the centre pipes to make the package shorter and cheaper to ship. And that includes Eternal Car. Sleeves are supplied to join them back together at installation. In theory it should be OK but in practice it's a pain in the a*** to get everything properly lined up. Even with a lift.
If you go the Klarius route make sure you immediately destroy the supplied exhaust hangers to remove any temptation to use them. Use original Vauxhall hangers. Or the Febi branded ones seem OK as well.