You need to undo the clamp just behind the cat. It’s easier to undo the clamp at the rear of the silencer too, undo the fittings to the tailpipe section and then slide that back from the silencer to allow the silencer to be pulled off the front mounting. Some twisting of the silencer and pipes will probably be required to release them!
It’s quite a straightforward job and I’d replace the support bobbins at the same time as they may have deteriorated.
