Cannot update G5 5587 BIOS from 1.6.1

Hi! I've been rather neglecting BIOS updates for a while and decided to update my system. After first trying to install the 1.9 update from my original 1.2.1 and immediately failing I started stepping and first went with the 1.5 and then the 1.6.1. However, at this point I cannot update any further and trying both the 1.8 and 1.9 updates results in a screen that, after restarting to begin the update, states that there has been an error and it is rebooting my system. How can I proceed from here? I have a Dell G5 5587 Ubuntu version. Current BIOS version 1.6.1. Thanks!