I would like to replace my older TIU - with a new one. The older one is set to TIU#3, and my SuperStreets are controlled by another TIU#2. Thus, the new one will be TIU#1 (my older TIU#1 bit the dust some time ago). Is there anything I need to do special-wise? Can I just swap out TIU#3 with the new one, or do I need to set it to TIU#1 (or are new TIU's set to #1)?