There are programs called that can load a rom image file from disk and have it "pretend" to be a real rom chip in the Amiga, it`s called soft-kicking. The ones I`ve used are for Apollo and Blizzard accelerators but there are lots so just give Aminet a trawl. You`ll need a 3.1 rom image from the same model Amiga as you have (the Amiga Forever ones won`t work).