Firstly, uninstall the application. You will need to bring up the Windows Add/Remove Programs screen. You can do that either by right-clicking it in your Start menu and clicking on Uninstall and then removing it from the Add/Removing Programs list, or by typing "Uninstall" in the Start menu and clicking "Add and Remove programs" and removing it from there.
Once the program is uninstalled we want to get rid of any residual files. For this we will need to bring up the File Explorer. You can press the Windows-E key combination, or find the File Explorer in your Start menu.
In the top bar of the File Explorer type %appdata%\..\Local and hit enter, as shown below:
In the list of folders that is displayed you will find a "Interplay Skilled Trades" folder (as shown below). Right-click it and click "Delete" to remove it completely.