Ok, that's a good starter...
So, what is your earliest memory of feeling this Social Anxiety? What was the situation? how old were you?
If you can run through the event from the point before you felt the anxiety to the point you started feeling it, describing it like you were watching a movie, in as much detail as possible. That will help to give you a phrase to tap on.
e.g. "When I was 6 at school and the teacher, Mrs Jones, gave us all a reading book and then we all followed while she was reading it, but then she asked me to stand up in front of the whole class and read from the reading book and everyone was looking at me"
This would give you a phrase like "Even though, The whole class looking at me when I was 6 and asked to read, I'm OK" (you can use the standard "I fully and completely accept myself" phrase if you like, but a lot of people find saying "I'm OK" or "I choose to be OK" works just as well)
It's important to consider your earliest memory of feeling the issue, try and put it in detailed words (but not too many), and create the phrase in your own words, how you "feel" about it, not how someone else has described your issue for you. As practitioners we learn (or we should, I've come across some who don't) that it's important not to put words into the clients mouth; the issue needs to be in their own words because that's how they percieve it.