SPikerzZ:
Here is the beta thread link with the instructions in case you had trouble finding it:
https://forums.taleworlds.com/index.php/topic,363475.0.html
The quote in the first comment has the full instructions, I'll paste it here:
"In the Steam Library, right click "Mount & Blade Warband" and select "Properties"
In the window that opens, navigate to the "BETAS" tab
In the "BETAS" tab, where it reads "Enter beta access code to unlock private betas:", enter the code betapassword exactly as shown
Click "CHECK CODE" and upon confirmation that the beta has been successfully opted into, select "beta" from the dropdown menu on the same screen
Close the window and allow the game to update
The Reforged Edition 2.025 beta will now be activated when you play Viking Conquest"
And agreed, the developers are AWESOME to keep updating it. Even if it is just bug fixes, them supporting their product so long after release shows great integrity.