Not so difficult if you really want it. I think this would be a relevant answer. Before the start of each season, we publish a link where you can apply for participation. Yes, I used "we" because I am now on the Science Battles team. About 6 months after my performance I got into the team. And that's just great! I have never seen a more interesting and cooler project at HSE. Well, at least for me.  Returning to how to become a member, I repeat that it is important to follow the updates in the VK group. We just finished accepting applications just recently, so a new season with new and cool exploration starts soon! Don’t miss it.