Changing Authentication Modes

I had a client who accidentally chose Kerberos instead of NTLM and wanted to change it. It's pretty basic.

Go into Central Admin, then Application Management, and then click "Authentication providers".

Then simply choose the web application you want to change, and click on the specific zone you are after modifying.

From there, simply choose the authentication mode from "IIS Authentication Settings" that you are after.

You can also go to a command prompt and change it by using stsadm -o authentication -url -type but that's mostly used to change from basic to integrated authentication.