Hi
To guide you completely through would be a bit too long, I presume. Do it step by step.
1) Jailbreak your reader
This will take a while, because you should read
that carefully.
Do as explained in the first post. You have to grade down your reader in a first step, because jailbreaking is not possible with the newest firmware.
Then jailbreak it. Then upgrade to the new firmware. Then install necessary software.
But, step by step. First: jailbraik your reader. It's not that complex.
Edit:
SSH is simple if you do it on a MAC. For windows you'll need additionally software you have to install on your PC. A MAC can do it without any need of new software to be installed. But without jailbreaking the reader - no luck.
Edit 2:
If you have a MAC, I can guide you through SSH. I have a PC, but never done SSH on Win. Just to be mentioned...