No special procedure that I'm aware of. I had the rear brake line completely removed from the rear caliper last season when I installed the modified swingarm and did not encounter any problems or ABS codes after the bleed was completed. I will be bleeding them using the gravity method which is IMO the best way to do it. I say that because I have tried Mighty-Vac pumps and such in the past and they do not work as well as this method for me. I also used this same method on my 2013 Mustang GT which had ABS and once again, no ABS codes or problems. The only thing to note is you should start with the caliper furthest away from the master cylinder (i.e. left front caliper and then right). The rear is separate and can be done before or after the front calipers.