How to rename - replace a User Control

I have a user control that I use in many forms. Now I have created a dll that contains many user controls. I don't want to maintain (2) programs.
The new library contains the original single user control.

In the project designer I want to make the following change.
Me.ComboRO_supplier_status = New OldLib.ComboRO()
Me.ComboRO_supplier_status = New UserCtrlLib.ComboRO()

I get the following error:
Value of Type 'UserCtrlLib.ComboRO' cannot be converted to 'OldLib.ComboRO'

I don't want to manually re-add all of the controls.

Any ideas on how this may be done?