The route begins from Boundary Lake; see the "Getting There" section of the main page for details.
A precise route description is almost impossible to give, especially as I spent a good deal of time backtracking from dead ends. Given the intricacy of the terrain in places, and general similarity of almost all possible routes that one will find, likely any description will be so vague as to be almost useless. So the following should serve more as general hints as to how to proceed...
Skirt the north shore of Boundary Lake, until you reach some large boulders/cliffs along the lake shore. Proceed north up granite slabs to head around these, avoiding the cliffs and tangled brush alongside the lake. From here, work your way up a succession of granite slabs, around boulders and a succession of small cliffs, generally aiming just to the right of the summit blocks for easier passage. Staying too far left along here can lead to either difficult downclimbing or backtracking to find easier terrain.
Eventually, near the base of the cliffs below the summit ridge, you can angle left to reach a small gully, consisting of class 2 talus and slabs. Climb this to the top and angle right, scrambling up some short, easy, unexposed class 3 ledges to reach the summit.
This route actually follows the west slope most of the way, before the final class 2 gully/class 3 ledges, which are probably more accurately described as being the (short) northwest ridge of the peak. This ridgeline can be spotted on the way up as the 45° slope leading to the summit; the ridgeline south of the summit consists of sheer cliffs.
Nothing in summer. A good map, compass, and GPS/altimeter may be invaluable for the approach during early season trips, when snow lingers along the forested and largely viewless Kibbie Ridge.