You need to remove the standard exhaust hanger when you fit Jardines. The Jardines fit to the inside of the rear foot peg hanger. You can download a .PDF file from the jardines website for the installation instructions but you definitely need the sticky'd advice on this forum and the manual for the header torques - 19nm from memory.
One thing I noticed on my 2008 classic is that when you remove the standard exhaust hanger, you loose the two location pin holes that take the torque from the foot peg. This is more of a problem if you have rivco relocation arms as I have. I drilled new holes in the foot peg hanger - which in the aft position is tricky and not pretty, but you can't see it when reassembled.