Installation:
(This is written on the premise you know how to get to your minecraft.jar / minecraft_server.jar)

CLIENT (minecraft.jar) -
1. Backup your minecraft.jar.
2. Delete META-INF.
3. Install ModLoader.
4. Drag the files in the "minecraft" folder into your minecraft.jar
5. Copy "HiddenDoors.props" into your /.minecraft/ folder.*
5. Start up minecraft and play.

* = HiddenDoors.props should generate anyway.

SERVER (minecraft_server.jar) - (NOT UPDATED)
1. Backup your minecraft_server.jar.
2. Install ModLoaderMp server.
3. Drag the files in the "server" folder into your minecraft_server.jar
4. Copy "HiddenDoors.props" into the folder with minecraft_server.jar in it.**
4a. Make sure your users have an identical HiddenDoors.props as the one for your server.
5. Start your server and play.

** = HiddenDoors.props will not automatically generate, and the server will crash without it.