In LB > Tools >Options >Updates
Those have to either be downloaded from within the LB media scraping, from our forum, or you can add them to your images folder from anywhere else you might get clear logos. From within LB if you select either all games in a platform or all your games the go to >Tools >Download >Update Metadata and Media for Select Games you can move through the media wizard and when you get to the image types just uncheck all and then check only "Clear Logos". Keep in mind it will all depend on the style of clear logos you want for the wheel. Specific one you can download from the forum. The LB media wizard usually downloads the versions that are just the png of the games logo.
It does require a bit of coding. There is another thread where I have a modified one for a similar style screen. I will see if I can find it and link to it.