After opening the application:
1 - Choose what do you want to edit (e.g "Drivers")
2 - Edit or Add information on table
3 - Save info with the "Save File" button on the bottom (You can save anywhere but to test the changes, the file must be on "Modding\Databases" Folder of your Motorsport Folder, e.g C:\Program Files (x86)\Steam\steamapps\common\Motorsport Manager\MM_Data\Modding\Databases)
4 - On Game, start a new carrer and when choosing race length, currency, etc... you will see on the top right corner a slider saying "Test My Mods". Activate it and you can test the changes you have made
Excellent tool if you just want to quickly mod and edit the attributes of the drivers, mechanics, engineers, and any file in the database without having to count comma delimeters, LOL! Awesome work!