syed 001:

Greg did it. I can do it, too. This is my SYED

Now, I don't think half of the things he did were scary at all. We all have different things we find scary.

So, start by making a list of things you find scary. 

His first scary thing to do was to go to a party by himself. Now, I do find that scary, but I am never invited to any parties, so it's not something I could do... perhaps I need to work a bit to get to that point. Hmm...

So - something similar; go to a Meetup meeting alone.

Take this as CBT - you go to the party to see what you need to train, practice, get better with, and what you like. What about parties you find annoying, boring, stupid, scary? What would make the experience better? 

It might be that you are shy and you are afraid nobody will talk with you. Then you should learn to talk with other people. Learn to mingle. Learn to be a good guest. Learn some party tricks. All this is just a question of practice. 

The secret of being an extrovert is finding others more interesting than yourself, being enthusiastic and open-minded, and having a streak of entertainer and exhibitionist in you :-D Now, the last one isn't something one should train if you don't have that streak. It's totally fine to be quiet and not the center of happenings. You can let the true extroverts have that scene. But finding people interesting is not difficult. See them as characters from books, for example, if you cannot see anything interesting in actual human beings. Also, being enthusiastic and open-minded - practice saying "yes" to most things. 

Another thing that makes your parties more enjoyable to you is to dress appropriately and comfortably and see you are clean and smell nice. And smile. Be friendly. Be open and welcoming.