oyu have to unscrew the the small screw at the bottom and one on the back. you then have access to both cables. You will also need to undo the top cable as this is held by a screw and a little plate.
The cable slip into position and are a bit of a bugger to get out a small flat blade screw driver I used. Reroute the cables making sure you have plenty of slack so you can turn the handlebars from side to side without it revving.
If they are to short try
Bellacorse for the America cables or have them made by them
