My friends and I are huge fans of the @Wiimm 's Retro pack released in 2015 (http://wiki.tockdom.com/wiki/Wiimms_Mario_Kart_Retro_2015-05). Unfortunately, some tracks have some slowdowns / glitches which have been patched in track revisions after May 2015. I assumed this would be an easy file swap solution since I am not looking to modify the tracklist in any way. I believe the custom track files are located in patch.tar\patch-dir\wu8-files\. However, I cannot find any documentation anywhere of anybody doing a revision transplant. Can someone please enlighten me if the following example is a valid modification to patch/create an unofficial Wiimms Mario Kart Retro 2018? Will variations in file size between track revisions affect the patcher or stability in game? My guess on how to proceed: 1. Download the CT pack (Retro 2015-05) 2. Download the track revision (N64 Royal Raceway 2.3) 3. Extract patch.tar from the CT pack and extract the .wu8 file (missing an extension) from the .wzb using 7zip 4. Using the wu8.list, identify the track number for N64 Royal Raceway 2.1 (in this case 56.wu8) 5. Replace the file. 6. Rearchive the patch.tar directory and run the ISO patcher Am I missing anything? Is there an easier/automated way to do this? Any ideas? Thank you!!