Yes you can do that by: 

1. Log into your sign it account 

2. Go to your profile by clicking on "Account" drop down on the top, then selecting My profile 

3. You can find the 2-Factor Authentication Section 

4. Click on Disable and then click on Confirm 

5. Go to your google authenticator app on your phone and remove that Signit Email from the authenticator as you can no longer use it.