Here you go fella, thou i had to do alot of reading and coming and going, here it is alot simpler
Do as all from first post on Page 1 by BK, til you get to "transfer the patched file to you PC" which is last part of root section of his post.
Now do as member Cyber Axe posted on page 3, i've edited aka added extra info for clearer instruction:-
Ok ladies and gentlemen I finally got it working, and here's what I had to do
You'll need to install 7zip and LZ4 program, that you can search on google, Put the LZ4 folder on desktop, aswell as all other files, will make it easier
(This part is continued from where original poster BK ends:- Once you've patched the AP file in Magisk Manager and copy it back to your pc, Open up that tar file with 7zip and delete all files except recovery.img and vbmeta.img
Then open the original prepatched AP file in 7Zip and extract the boot.img.lz4 then take that file and drag it onto the lz4.exe from the lz4 utilities
you should now have a nice clean uncompressed boot.img, put that back onto the phone and patch it with magisk manager, you should now have magisk_patched.img copy that back to the pc and rename it boot.img and put it in the tar file from earlier so you should have boot.img recovery.img and vbmeta.img
With just these 3 files in the tar you dont have to worry about wiping your data again and it will patch pretty fast
Open up ODIN again and select AP and choose your new tar file and flash it
Then shut down the phone fully and power it on while holding vol up till you get to the warning screen about the unlocked bootloader let go of vol up and press power to continue and you should find that it boots properly now and magisk manager will show that magisk is installed. (It is this part only where it did not work for me, so follow what i posted)
After numerous loops, i went into Download mode, opened ODIN, i put in AP the already magisk_patched.tar
Then from non-patched official firmware files, i put in BL, CP and USERDATA the HOME_CSC.
Leaving CSC empty.
Flashed, went into recovery by keeping the VOL up button pressed after pressing power button after bootloader warning screen, in recovery i selected MOUNT, rebooted and a message came up no OS, so booted back into recovery, then i pressed wipe data reset & Shut phone down.
Booting up pressing aka keeppressed vol up and power buttons, til bootloader screen comes on, then pressed power and it booted normally aka samsung logo will appear shortly.
I then installed Magisk manager which is not mentioned anywhere in tut, but on this occasion i am, as, when i started it aftter installing it, both Magisk is upto date and Magisk manager is upto date now show.
I installed adaway my fav ad blocking app to test for root and root was granted
A good thing about this root, is that You don't need to press up and power in order to have magisk, just normal power button press
