Erulin

Since recently my Spider Jam is stuck on the MCU VERSION 1.05 screen on boot up.... I have tried a factory reset but that doesn't work. I have read that I should perform a firmware update, which I'm willing to do... but... to perform said firmware update I'm told I have to navigate the menu (via the save button) to the Firmware update button... but how can I actualy reach that menu seeing as my amp is stuck on the Version screen ??