It's all relatively GA. There are ushers at the top of each section that are supposed to review ticket sections and such, but they tend to allow you through if you have the orange colored supporters section ticket. If they are one of the stringent few, you just go down the staircase for your ticket's section and then walk over a section or two to be with your friends.
Example: Your ticket is 235, but your friends are in 237. Just go to section 235, show ticket, walk down a few stairs, and then walk over/across 236 and then 237 to meet up with said friends.
Thanks. Makes sense.
You must not read many of my posts -- if you had, you definitely wouldn't have used an example based on "having friends".