**WHICH** tutorial? Link please, because we have more than one.
This one:
http://lifehacker.com/how-to-jailbre...dle-1783864074
Standard questions in that case (durn, I need an electronic rubber stamp):
First six characters of your device's serial number.
Link to the update you are trying to use.
The first 6 are 9017 22, I tried using the Paperwhite 6th gen version 8.4.3.2 from the Amazon website:
https://s3.amazonaws.com/kindledownl...5660001.tar.gz
I also tried the 7th gen version, since I wasn't sure what my Kindle had:
https://s3.amazonaws.com/kindledownl...5660001.tar.gz
After I wrote the thread, I reset my kindle once more, which brought it to the downgraded version, connected it to the wifi and left it there. After some time, I could press the Update your Kindle button, and it upgraded it to a 5.6 version. I did it once more and it got the latest one. It has no jailbreak but I'll definitely try again when I have some better guidance.
Thank you for your help!