[shamanNS]

It somewhat counter-intuitive (using / running MRPI before you have functional KUAL, even more so when you're doing that to install KUAL itself ).

But basically you do this:

1) download, extract and copy over to your Kindle both MRPI and KUAL files (you need to use "coplate" version od KUAL booklet package) from the sticky thread for @NiLuJe's snapshots.
2) on Kindle in search bar type ";log mrpi" (without quotes) and execute the search (by pressing an arrow icon or whatever is used on that newer UI). It should start the KUAL installer and writing stuff on the screen.

The jailbreak has added that search command / script shortcut (;log mrpi) thing and now you have that alternative way of starting MRPI (the primary way being using KUAL to start MRPI).