Direct start is possible, but I suspect most folks angle in from the right and wire the bolt. Doesn't get done much judging from the friable flakes and the cleaning I did. I led up to the ledge and belayed from gear in a horizontal crack to watch the action. (The last bit to the top is maybe 15 feet of easy climbing.) It's probably 2 stars, but not worth the walk by itself. Good to do after CC.
Location
Mister Sol is the left most climb on the "South Face" (faces West, if you ask me) of Asshole Rock; maybe a minute's walk left from Cardiac Crack. It's a good looking, straight-up, thin crack with a hangerless bolt up off the deck, just right of the crack. Descent is a walk off down the slabs to the north (left) to a tree, then hard left through a cleft next to the wall brings you right to your pack.
Protection
Small to medium nuts and small cams; maybe up to a #1 Camalot works. Hubbel says up to 3 inches, but I didn't bring or use one. Definitely bring a wire to saddle the bolt (the nut is on it).