Hi Jkyds,
The problem at the moment is being able to EXTRACT the firmware from your player. You have the newer 9.1.52 firmware which unfortunately the s1fwx tool (used for firmware extraction) doesn't read properly. So unfortunately unless you are able to extract the firmware from your player, modifying it is difficult.
You could try someone else's firmware or another firmware, however, you risk a high chance of a DEAD player by using an incompatible firmware.
Hopefully the next release of s1fwx (
www.s1mp3.de) will read your firmware.