Clean small sections at a time, and change cloths frequently to keep the old finish from being reapplied to the furniture. When the finish is off, go over the entire piece with a scraper to remove any remaining traces of finish.
1 2am:The Yorba Linda, CA forecast for Aug 14 is 70 degrees and Clear. There is 80 percentage chance of rain and 3 mph winds from the Southwest.  5am:The Yorba Linda, CA forecast for Aug 14 is 68 degrees and Clear. There is 85 percentage chance of rain and 2 mph winds from the South.
Here are the average temp in Yosemite Valley (where CV is located) by month: www.nps.gov/yose/planyourvisit/climate.htm. Also beginning of September is usually still quite warm. Nights can have a bit of a chill, but nothing a couple of blankets can't handle.