Follow the directions on the main page to the Gilpin Lake trail. Hike towards Gilpin Lake, but shortly before reaching the lake leave the trail and strike off cross-country northward. Follow Gilpin Creek towards its western source, a lake at just above 11,000' to the south of Big Agnes Mountain. The eastern source of Gilpin Creek is below the west face of Mount Zirkel at lake 10819 on the map.
Please follow Leave No Trace guidelines when traveling through such a pristine area.
From the 11,000 foot lake make your way up the broken face to a saddle at 11,400 feet. There are various class 2 and 3 (or perhaps even harder) options, so you can pick a route that suits you.
From the saddle make your way eastward to join the obvious ridge coming directly down from the summit. Up you go! It's no more than a scramble.
The views north to the Sawtooth Range will have you planning future trips to the region. I am tempted to offer a money back guarantee if you are not alone on this mountain.
No climbing gear required for a summer ascent.
Have fun. Be safe.