All transactions and information attached to an account is connected by the customer's name, not account number. So if you ever come across the need to change a customers name, go into the customer file, F4 edit and enter in the new name and press enter or tab. The system will prompt "Are you sure you want to change from the old name to the new name" - Select Yes.
It will then ask "Update Workorders and Sales history y/n" - Select yes again.