I’ve just noticed that the reach adjuster for my 2015 Guide R’s has been knocked around and trapped in the lever body. This is stopping the levers moving out and is holding the brakes fully on.

I’ve tried some gentle to medium persuasion to try and get it to pop back, but have yet given it some real welly for fear of snapping it.

Anyone got any suggestions on how to resolve?

Remove from handlebars and remove the lever blade from the brake body, assuming the lever pinch bolt is accessible (“pinch bolt” in the image below, holds “pivot pin”):

This sounds like the common fault on these Guide brakes. SRAM have been replacing them under warranty. It seems to be something to do with the piston assembly, which some say is worse in the heat (proper heat, not our summer temps!). I’m probably going to replace the piston if I can source one.
There was a recent thread on here http://singletrackworld.com/forum/topic/the-non-returning-guide-lever-saga

In this case it is the reach adjuster that got bent / rotated 90 degrees that’s preventing the lever from returning.