Shortening exhaust outlet

[Scotty]

Bought an HP CORSE evoextreme exhaust and link pipe that was assured came off a gen 2. Tried to fit it as a slip on (attempting decat when have more time in the summer). The exhaust pipe diameter is correct, but the inlet on the exhaust appears to be 5cm compared to the 7cm of the standard oem exhaust. This means the bracket hole doesn't quite line up as the pipe can't slide on the extra 2cm. Would it be feasible (without big issues) to take that 2cm off the pipe that exits the back of the cat to allow the pipe to slide down enough to line up with the bracket?