Changing Internal Banks - suggestions on what to do procedurally

Changing over Internal Banks that we use to Pay Suppliers and Receive cash from debtors.

The changeover will happen on the 1st of August.

I'd like to know if there is a procedural check list that is recommended when doing so. The object of the exercise is to completely close off the old bank and then use the new bank. They don't want to be running with both banks at the same time.

Any help on procedures/check lists etc would be greately appreciated.

thanks