They charm magic, singing quickdraw fairies to take them up and use holes make by cliff dwelling gnomes for the bolts
<sorry, rough day>
The hard part is not getting the draws there, the hard part is placing the bolts in the first place, drills and bolts are HEAVY. They use a variety of aid/trad gear, sometimes top down (if they can, sometimes the terrain doesn't allow it) otherwise bottom up, drill all the holes then put in all the draws.
When cleaning overhanging routes they get lowered as you would normally, but they clip themselves to the rope running from the belayer to the chains with a draw. This keeps them close enough to the rock that with a little bit of work they can clean the route. If you do this, remember to unclip from the rope before you unclip the last (lowest) draw otherwise you will drag your belayer across the ground.