I've seen a myriad of schemes that all claim to reset the furthest read page (without cracking the book—converting it and/or basically making it new). I've tried them all. The only fool-proof way that works 100% of the time is:
Originally Posted by mewmartigan
I had to contact Kindle customer service via online chat and have them reset the furthest page read.
It really should be a feature by now.