It would be much easier to do if you remove the rear wheel. As Blaine C said, you will need to remove seat, unplug wires, they feed through a grommet in the rear fender and then are held in place under the fender by metal tabs which will need need to be bent out slightly to remove wires from under the fender. The other alternative is to cut the wires on old blinker close to blinker, cut wires long on new blinker and solder/splice new blinker to old wires left in place. Your bike, you make the choice