SRAM Guide R brakes pad adjustment I've replaced my old brake pads in SRAM Guide R brake set, and I've noticed that the old pads were sitting much closer to the rotor than the new ones (I've also definitely used all of the old pads). As a result, now the rotor is being squeezed by the new installed pads. 

How can I adjust the pads to the desired (more space between them) position? Could I just release some brake fluid (while bleeding) to decrease the pressure in the system and hope that it would pull the pistons back? Or is it more likely that my system is contaminated and I should clean the pistons?

Looks like this:
You did push the pistons full back into the calipers before installing the new pads, right? That should provide enough room for the new pads.

There seems to be a widespread misunderstanding about how hydraulic brakes work which leads people to think that removing some fluid will make more space for pads or set the pads further apart.

You cannot reduce the amount of fluid in hydraulic brakes, because it is variable and has a reservoir in the lever units to draw from. Fluid is drawn in to compensate for brake pad wear and gradual advancement of the caliper pistons. Also, fluid can move back and forth as the temperature changes and the fluid expands or contracts.

The way this works is when the levers are at their 'at rest' position the reservoir is connected to the lever cylinders by a small hole which allows fluid to move in or out. The first part of the travel of the lever piston in the  cylinder cuts off that hole to the reservoir and seals the system. Then, as the lever piston applies pressure the caliper pistons are pushed out to apply the pads against the rotor.

The small hole connecting the lever cylinder to the reservoir also allows you to push the caliper pistons back in to the calipers when replacing the pads.