its easy... if you already have the clear turn signals, just take a screwdriver and go through the middle of the grill, and you should see where the screw is, its on a diagnal facing out towards the grill, unscrew it, and the turn signal should be loose and you could pull it out very easily. Then, unplug the light from the turn signal (turn and pull out), and then grab the clear turn signal, put the light back in the same way you took it out, mount the turn signal back into the bumper, and screw it in.
ill take some pics of where the screw is for you in a few, hope this helps, later man.