West Ridge

This route is rated class 3 in guide books, but expect class 4 climbing in multiple spots. 

Start up the ridge until it becomes more technical, drop down a bit to the south side (climber's right), along class 3 ledges. As the ridge sharpens head back up to the crest, to a notch, across a low angle slab, then back off the crest on the south side. A little further it gets a bit tricky keeping it less than class 4 and finding the best path. This was the crux section for me. I took a sort of undulating line across the last section, to below where the summit is, then headed up class 3 and class 4. 

(There is a detailed description of the route on SP)

Descent:  You can go back down the West Ridge. Or, even better, continue along the ridge, past the summit a little ways, to the first major notch (or a little before), and head down slopes, taking the best line, to above Sam Mack meadow. This option is quicker and easier than descending the West Ridge. 

Start from the saddle between Mt Agassiz and Mt Robinson.

Scramble.