How can i delete my MIK library
If you are using a Mac, click on your Finder app, then press command shift g to open the "Go to the folder" window. Paste in ~/Library and then look for the Application Support/Mixed In Key folder. Delete all Collection.mikdb files that correlate with your version.
On Windows, the file that needs to be deleted can be found in C:\Users\YOUR USERNAME GOES HERE\AppData\Local\Mixed In Key\Mixed In Key\YOUR VERSION\MIKStore.sdf file.
Please note that the AppData folder is a hidden folder, so you will have to set your PC to display hidden files and folders to see it.
Let me know if it helps :)