It's easy to move the turn signals to that general area, but they're usually attached to a license plate bracket as part of a fender delete. Since those look like stock signals, I'm guessing they just fabbed their own brackets for mounting.
re-route all blinker wiring underneath the seat
re-route license plate wiring to new after market license plate holder
put hole in the plastic panel below the seat facing rear tire
install the blinkers with some kind of DIY metal mount.