Reject love confession from a friend.

So how do you really reject a love confession from a friend? I say friend, but we're not really close, more like we just have the same circle of friends (from highschool). The thing is, I'm very awkward and well... an introvert so... you know? He previously
confessed to me before (like 2 years ago) and I thought I was pretty on point I wasn't interested given how I rarely respond to his messages and I almost completely ignore him. Things got a lot awkward between us, then he stopped messaging me for a long time now, but all of a sudden just yesterday I received a message from him saying that he missed me and that he wants to try to "woo" me again. So, I would like to ask you guys, how
should I respond to this?