Step 1use retroarch playlist generator (a seperate downloadable tool) to scan the folder where all games of x system are located, be sure to set it to prompt on everything, and to uncheck use file name and text as box art.steep 2check to see if the rom hacks are now listed if yes go to step 3 if no repeat last stepsteep 3take an alredy working boxart, open in photoshop, make two new layers, delete the base layer that has the other games box art. make your own box art now in the new empty layers ether with your mad art skills or import and place shit from google image serchonce happy with your new creation save as a png named the same name as the game, save to the named boxarts folder. should work