[Bobcat]

Dugly ... don`t know about the Wilwood calipers , but the Sierras on mine are pretty simple .... and yours should be basically the same . My "O" rings are actually square . To get them out , take the calipers off and use compressed air in the inlet port and one or more will pop out . Put a small piece off wood inside the caliper to keep the pistons from going all over the place . My guess is that Willwood has much the same setup and disassembly will be similar .
As far as bleeding sequence , ERA uses the same sequence . You want to bleed the longest lines first and then go to the shorter ones . If your calipers have bleeders on the inside and the outside , bleed the inside one first and then go to the outside one , making sure the bleeder screws are vertical .