How do I remove a Userid from my Intuit account? I apparently have two ..

Each TurboTax user ID is a separate account. You cannot remove an account. Just pick the one you want to use going forward, and ignore the other one.

I have two login ID’s attached to my account.  I want to remove one of them for security purposes.  How can this be done?

Only one User ID is assigned to a TurboTax account.  If you have multiple User ID's each one is for a separate account.  TurboTax accounts cannot be deleted so abandon one of the accounts and only use one account going forward.