If your destination is the pass itself:
From Source Lake, head up to the Great Scott bowl. Once you enter the bowl trend hard right and traverse below Bryant Peak on the north side.
Cross over the low point between Bryant and Chair, drop down heading north to meet the climbers path just below the pass.
If you are heading south from the pass, this is, of course a silly way to do it.
I have always wondered if you can reach it by traversing under the N face of Chair Peak. Then over the NW shoulder at it's high point and down to the pass.