You can add/remove discs. Insert your images simply by right clicking the image holder layers (marked in red), called "image1_design, image2_design and image_holder". You need 3 images: the cover one (590x806), and two round images for the discs (890x890) that you will just paste in the smart objects marked in red. You get 2 PSD files - with 1 and 2 discs.