The bulk of the instructions for this method presently reside in the community thread forum here:

• http://thec64community.online/thread/270/c64mini-mode-hack-uart-needed

• Mobluse shared this video on using FEL-mode:
  • https://www.youtube.com/watch?v=VFdwbv87g9Q&t=971s

Here are a few cherry-picked additional aspects of that thread placed here, just for convenience:

On page 5 of the thread, jj compiles MidnightCommander, available here:

• https://mega.nz/#!tssSzAKZ!UKrYBrFkE1ni99Qw9qYZAgmlYvS8tQEPcmiQF2b07HI

On page 6 of the thread, jj compiles the ELinks text-based web-browser, available here:

• http://res.cloudinary.com/jj0/raw/upload/v1548597047/elinks.cpio_q0ymjc.gz