Also, replacing your eMMC is going to be very difficult. It's BGA soldered to the board which makes removal pretty easy, but fitting a new chip almost impossible, especially if all you have is a heat gun. You might be able pull it off if you pick up a solder paste stencil for the eMMC chip and squeegee on some solder paste, but it's still going to take a bit of luck. You'd also have to jump through all kinds of hoops to get the Kindle's OS running again with the new eMMC.
A user on here by the name of zephray was able to pull it off though, here's a link to the post he made. I'm currently trying to upgrade my own PW2's storage to something in the range of 32GB to fit all my weeb comics.
https://www.mobileread.com/forums/sh...d.php?t=271750