I assume you would like to start over and create a new database.
There is no need to uninstall the application itself, simply remove its data folder.
Here is how to do this:
- Hold Control key down and select 1Password > Quit 1Password and 1Password mini from the menu.
- Open Finder and select Go > Go to Folder menu. Type ~/Library
- If you have the Mac App Store version of 1Password, go to Containers folder and rename this folder
2BUA8C4S2C.com.agilebits.onepassword-osx-helperto something else.
- If you have the AgileBits store version of 1Password, go to
folder and rename the 1Password 4 folder.
- After that, launch1Password again and start over.