How to disable MFA in Salesforce?

If you are looking for disconnecting or revoking MFA for just a single user, then check the following link.
 
If you are looking for disabling MFA for multiple users part of a profile or permission set, then check the following steps: 
 
1. In the Profile or Permission Set, Disable "Multi-Factor Authentication for API Logins" and "Multi-Factor Authentication for User Interface Logins".


2. In the Profile or Permission Set, set "Session Security Level Required at Login" to None.