How to Play Mods

Downloads
You will need to download the mkdd track patcher and any desired mod .zip files. You will also need an Mario Kart: Double Dash!! .iso file, which you are on your own to find. One everything is downloaded, extract the mkdd track patcher .zip, but not any of the mod .zip files.

Using the Patcher
Open patcher.exe. You will see three fields: The input .iso, the .zip files and the output .iso in that order. First, choose the .iso that you wish to patch. This .iso will not be overridden. You will see that the third field is automatically filled out. It is filled with .new_iso.iso, and appears in the same directory as the chosen .iso. You can manually change this output path, if desired. It is recommended for you to patch an .iso that is not on a USB disk, because that can slow down the program. For the second field, choose any .zip files that you wish to patch into the .iso. This can be one or multiple mods.

Finally, hit the "Patch" button at the bottom.

Troubleshooting
Several errors and warnings can occur in this process:

If the program says that some .zip files were excluded due to not being mods, it means that the .zip itself is problematic, and there's not much that you can do. However, if you notice that the mods not being patched in were from Google Drive links, make sure that you downloaded the actual .zip file in the linked Google Drive folder, not the folder itself. If the program says that there are conflicts, it means that some mods are overriding the same files. See below on potential fixes. If the program is taking too long, and you are patching an .iso on some external storage, try moving the files to internal storage, and patching from there.

Resolving Conflicts
Suppose you have multiple mods that are currently trying to override the same file. You may have some solutions. If you are trying in patch in non-track mods, then there's not much you can do beside some heavy renaming on your part. If you are trying in patch in custom tracks, then you can fix your issue, provided that you are trying to patch in fewer than 16 tracks.
 * 1) Identify the tracks that are in conflict with each other. Most tracks have a recommended slot on their page, but you can identify exactly which track is being overridden by looking at the trackinfo.ini file in the downloaded .zip file
 * 2) Edit the trackinfo.ini file of one of the conflicting mods.
 * 3) Change both the "replaces" and "music replaces"