Delete custom site column added to field collection

<Field ID="{E8D04C0B-2160-4F2A-B074-FCED8F985E41}"
       DisplayName="ProjectOwner"
       StaticName="ProjectOwner"
       Name="ProjectOwner"
       ReadOnly="FALSE"
       Required="FALSE"
       Hidden="FALSE"
      Type="user"      
       Mult="False"
       SourceID="http://schemas.microsoft.com/sharepoint/v3"
       Group="Columns"></Field>

I had accidentally deployed this custom field type as "user" instead of "User" and ever since i have been unable to open even the application page used for viewing the site columns.
i tried writing up a c# code to delete the column 
web.Fields[new Guid("{2194E822-9DE8-4E86-91E2-9F8D7452462C}")].Delete();
but it does not recognise the field and throws an exception "Field user type not installed properly"
* tried to open the site columns using sharepoint designer it doesnt open either.
Any help is greatly appreciated.