So how do i try this?

A) I am jailbroken and on version lower than 5.16.3

Install latest softfp hotfix from Nilujes snapshots thread, upgrade to the desired version and install the hotfix from down below. You should be good to go.

B) I am not jailbroken and there is no jailbreak available on my version

You cannot try this :(

Hotfix - modified to support HF - do not install this on non-hf FW versions you wont be able to use gandalf and fbink

MRPI - modified to support HF - rebuilt kindletool, libz and fbink + added hf detection - should also support any kindle normal mrpi does

KUAL - straight from nilujes thread

KOReader - nightly builds for khf - might not be latest try to update after installing :) - defaults to my nightly server

KOL frameworkless - straight from yparitcher/kual-booklet

KOL asap - straight from yparitcher/kual-booklet

coversetter - pretty icons for your kual and kol - from Stanner on MR

renameotabin - fuck you amazon this update is cozy - from hius07 on MR

downgrade script - ;log runme - fuck get me out of this hf bullshit - adapted from darkassassinua on MR
* NOTES:
run with ;log runme then wait for it to reboot after that place your update-****.bin in userstore of kindle and force a reboot
after the downgrade make sure to install non-hf hotfix (assuming you are going to fw <= 5.16.2.1.1)

USBNet-lite - just like usbnet jsut much much simpler