Uncover the bleed nipples. Note there are two up front for our 6 pistons callipers. One on top of each side. I backed off this one and pressed the pistons back. Then I closed it and opened the other side and pressed the pad on that side in. As mentioned you can then have someone press on the brakes after you have topped up new fluid and closed the reservoir and inserted new pads with hardware so as to bleed the calliper and the brake system of any dirty fluid using the hose line and container.