Lowering Off A Bolted Route
Lowering off at the top of a bolted route and retrieving your rope without leaving any kit behind can be a potentially fatal manoeuvre. The following procedure allows you to remain connected to the rope, and thus belayed throughout. Also you can't drop the rope.
Use a 4ft sling larks-footed through the stitched belay loop of your harness. Clip it using a screwgate carabiner to one of the lower off bolts. (Clipping the higher bolt will draw you in closer to the system).
Pull up a loop of slack from your belayer, making sure you remain on belay, and thread it through the higher bolt and then the lower bolt.
Once the bite has been passed through both bolts of the lower off, tie a fig of 8 in it. (An overhand will do but may be difficult to undo after lowering). Use a screwgate to clip the fig of 8 on the bite back into the stitched belay loop of your harness.
Having now clipped into the bite of rope, and done the screwgate up, untie the knot you climbed on.
Pull the tail through the bolts (effectively the tail of the knot on the bite). Check the belayer is paying attention and has you locked off, or is holding the dead end. Remove the 4ft sling and screwgate and hey presto you are ready to be lowered.
Make sure you remain on belay throughout.
Check you haven't clipped the bite into any of the gear loops, a potentially fatal error!
Practice procedure on terra firma substituting a couple of carabineers for bolts.