@Jiryn Yeah. If your computer is on the same network as your Pi (and the Pi is running) you can access it via your web browser of choice. I've had it activated for so long I'd forgotten how to make it work, thankfully @ETAPRIME has that covered:
Once active, you can drag-and-drop your BIOS files via the web page. If they're not what RetroPie is looking for it'll tell you then you can seek another source. Saves the time and hassle of repeatedly booting up your Pi to see if you've fixed the problem.