Adding associate member so they can ride along?

[Wingrider]

I'm reading more of the event docs and while I'm a NorCal member, I added SAAC national membership to my SAAC 43 event reg.

It looks like I need to add my family member as an associate member to get them on track with me.  How do I add that before the event so I don't have to pay the mandatory daily adult guest fee, and the wristband so they can ride along.

Thanks