3. Client/Server Modding

To modify client/server for your instance, you need to use RetroMCP.

Download links can be found on Introduction page

Steps

1. Install JDK 8, RetroMCP, and VSCodium.

2. Run RetroMCP-Java-GUI.jar.

3. In 'Current version', select 'Beta 1.7.3' and wait for the setup to finish.

4. [Important] Go to the `jars` folder, copy `minecraft.jar` and `minecraft_server.jar` to a safe place as a backup.

5. Open the source code in VSCodium and modify the links using the guide below:

Exact file locations

6. Click "Build" in RetroMCP to compile your custom jars.

7. Your ready-to-use modded jars will be waiting in the `build` directory.