[Zeke]

You are taking the 405 anyway, not the 5, and then north on the 133 (Laguna Beach Fwy) to the 1st off ramp. Do not miss the off ramp or you will be on a toll road with no place to exit. That 1st off ramp is Gateway and leads straight to the event. The off ramp says "Barranca" but it's not Barranca you land on. Just go straight.

Or you can use the surface roads, but you will wind around and get lost unless the GPS is better than what they used to be.