2004 Range Rover exhaust modification
 

I need some technical help please. I have a 2004 Range Rover Vogue 4.4 and I have just purchased Remus performance exhaust pipes for a sportier look more than anything! The guys at Remus told me that the rear box and pipes will fit simply into the existing clamps and that I could probably do it myself if I don't mind getting my hands dirty!
When it comes to removing the original rear box,is the OE box welded to the central exhaust line or will it simply slip off?

cheers