LCDColourMPXFMSlim,
Why are you trying to upgrade your firmware? Are you having problems?
Upgrading your firmware will not add any new features to your player and you risk rendering it unusable and unrecoverable by trying to do so.
Each players firmware is unique its components and you have about a 1% chance of finding another firmware that will be fully compatible with your player combination of hardware, which leaves you a 99% chance of bricking it.
Before you attempt any alterations to your player be sure to backup your original firmware with s1fwx which you can download from
HERE and there is a guide to using it
HERE.
Please describe what you are wanting to achieve as there are some things that are quite safe to do.