Error When Trying To Delete User

I created many test users in my application while trying to get a custom registration process to work, and now I would like to delete those users so they don't use up space in my database. When I go into the aspnet_Users table and try to delete a user, it gives me the following error:
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DELETE statement conflicted with COLUMN REFERENCE constraint 'FK__aspnet_Me__UserI__0F975522'. The conflict occurred in database 'DB_83996', table 'aspnet_Membership', column 'UserId'.

DELETE FROM [DB_83996].[dbo].[aspnet_Users] WHERE 1=0 OR ( [UserId] = '{7E864A07-6FE8-46EF-A2B8-354646D57C76}' )
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I don't know much about SQL statements, so is that statement it gave me the statement I need to use to delete that particular user? If not, how would I go about deleting these users I don't need anymore?
Thanks so much. :)