To get on the Cascadian for descent- 
There were cairns (2 weeks ago) marking the whole thing out for you. Scramble off the east side of the summit- go back up, to the base of the false summit, then descend. Again, the whole thing should be clearly marked. I brought a photocopy of the the page from the brown Becky book, showing the entire south side of the mountain- this should be helpful.