You'll probably be ok with the GPS, but take their phone number with you too, just in case. First time I went there (before I bought a GPS), I was driving up and down Almaden (expressway) looking for it, not realizing that it was actually on Almaden ROAD, a poorly marked side street.
Ya, it's sorta confusing to find. You actually have to look for the fork in the road. It's in the middle of a small industrial area in an old school house on the corner. Be sure to call. I'll text you my number so you can call if you need to.