If you have a nice stainless exhaust and keep it polished then why keep it hidden?

First of all remove the rear valance. You then need to remove the two lower rear brackets (held to the crash bar with a Torx T45 on each).

Then grind the corners off each (as per photo), as this will allow you to bolt them back at an angle so they will not be seen when the rear panel is refitted (see below).

Cable ties can then be used to secure the rear panel to the brackets.