Heyno problem! No, a graphic program can't read pssg file. To open the pssg file you need EGO PSSG Editor. With this tool you extract the graphic files like car skins/helmets which are .dds files. For graphic programs like photoshop you may need some extra plugin to open these .dds files (just google this plugin for your program). Then you can edit them easily
It works now with paint.net. I finally can change liveries now just not the flippin' car number.....if anyone edits car skins using paint.net, how do you change the car number on the skin?