This is a very simple tool. It can uninstall Unlaunch in just a few seconds, all you need is a decrypted NAND image! This tool has an untested feature that will install Sudoku+Sudokuhax. (You will need to get the .app file yourself) This is a .bat file, and you can easily see the source. I have left a lot of info about the program in the Readme, so be sure to read that. This tool is very safe. Please test your NAND with NO$GBA before you flash it to your DSi! That is the easiest way...
[Release] Relaunch
[Release] Relaunch