DCI: Last Alliance is a submod for Third Age: Total War, focused on the War of the Last Alliance in the Second Age of Middle-earth.
1. Download DCI_LA_installer.zip and extract/unzip the contents.
2. Run DCI_LA.exe, it will automatically find your Medieval II Total War folder. If it doesn't you can manually browse and find it. Proceed with the installation and when prompted accept and overwrite any files and folders.
3. At the end of the installation a cleaner will delete files that need to be auto-generated at game launch, you'll be prompted to 'press any key to continue...'
4. Likewise, a shortcut for 'DCI: Last Alliance' will be created and added to your desktop, you will be prompted to 'press any key to continue...'
5. Launch the mod by double clicking the 'DCI Last Alliance' icon on your desktop or the DCILA.bat file (DCILA_NoBaiSwitcher.bat will run DCI:LA without the battle AI switcher).
Optional: delete the Third Age Total War shortcut from your desktop if you have one.
Optional: open your cfg file and switch the [log] level from trace to error.