Reset a player's progress on a server

I have a Minecraft server I've just started for a few friends. We're playing on hard, and I'm going to set it up so that players spawn with a few minimal items to get them going. Some of them jumped in briefly and logged out after less than 5 minutes last night. How do I reset their progress so that when next they log in, they spawn as if they have never logged in before and have the items I set new players to spawn with?

I.E., how do I make the server forget that they were ever there?

Solution 1:

If you remove the files in the world\players and world\stats folder, the server will forget that they were there. If this is a bukkit server, there is a players folder in each world. Files are named with the ID of the player, so you can delete selectively. To get the ID of a player, open https://api.mojang.com/users/profiles/minecraft/(playername) (substitute (playername) with the actual player name)