TL;DR - skip to the STEPS section
Kingroot and Kingoroot are two completely different apps, made by two completely different group of developers.
Kingroot, while it is probably the leading app for "1-Click-Root" solutions, also installs a ton of bloatware and annoying services that you may or may not know about.
Kingoroot I can't really speak too much about, considering there have always been many other solutions to achieving root including Kingroot.
Okay so I've used this method dozens of times and it works 99% of the time. The only time I haven't had it work was for a Verizon HTC One M8, since Kingroot only gives (at least at the time) temproot it took a few tries to get it working properly. I give all credit to w0lfdroid to finding it, and the original guide can be found here http://www.w0lfdroid.com/2015/05/How-to-Remove-Replace-KingUser-KingRoot-with-SuperSU.html
This may leave your device in an unrooted state, if this happens then just run Kingroot again and it will fix itself.
- Download the following three items:
--(Terminal Emulator App / Alternatively you can just use ADB shell)--
--(Zip archive containing necessary files / v1)--
--(Zip archive containing necessary files / v2)--
- The two zip archives contain the same files, but if the steps don't return the desired result using the v1 files, then repeat the steps using the v2 files.
- Extract the "mrw" folder from the zip archive and place it anywhere in "/sdcard". For convenience let's just say you're not using a computer and instead doing this all from the phone you're wishing to switch from Kingroot to SU. Downloading the files will put them inside /sdcard/Download. So navigate to there using the built-in file explorer (or Root Browser if you don't have one), extract "mrw" from the zip, and proceed to install Terminal Emulator.
- Open Terminal Emulator and type the following commands:
- This will return a ton of text and quite a few errors, don't worry about it, I've never had it not return some errors. When finished it will install SuperSU automatically and open the app, asking you if you'd like to install the necessary binaries. Tap "Yes" and choose the option that is NOT to install in recovery.
- At this point it will go one of two ways: either the binary installation will fail, at which point you'll have to re-root with Kingroot and repeat the steps using the other zip files; or the binary installation will succeed and you'll need to reboot the device. Upon booting you will see Kingroot and all associated files have been removed, and replaced instead with SuperSU.
If neither of these methods work there is a paid app in Play Store called Super-SuMe that's supposed to be specifically made for removing Kingroot and installing SuperSU, although despite purchasing it multiple times I have never once had anything happen besides either a reboot, force close, or the app hangs.
Best of luck.