How to root after you take the OG5 OTA update

Some tips for those who already took the OG5 OTA update and want root (will be obvious to most of you, and most of this has already been covered in other posts, but some might benefit from this guide with download links included):

1. Copy the BeastMode kernel zip to your phone or SD card.
2. Start Odin3 v3.10.6
3. Place the TWRP tar in the BL slot
4. Uncheck Auto Reboot in the options tab
5. Flash TWRP -- when it's finished flashing, disconnect USB and pull the battery for 10 seconds (on my phone, if I put the battery in too soon, it boots without pressing the power key)
6. Put the battery back in and boot to TWRP
7. Install the modified kernel zip you copied in step 1.
8. Since you're in TWRP, might as well clear the cache.

TWRP should ask you if you want to install SuperSU. Say yes even if you already have SuperSU installed on you phone.

Reboot the phone, and if necessary, install SuperSU from the play store.

My phone complained about "KNOX has unfortunately stopped", so I just used Titanium to freeze all the KNOX apps, which cured that.

Be very patient the first time you run apps that request root. It will pop up the "grant" dialog eventually, but sometimes it's slow to do that after a boot.