First of all, thanks for reading this doc!
Open a new issue with Request new bank template, and fill in the information of the bank in the issue. The template already asks for all the needed information.
The data is updated daily using a tool called MergeTool. If you are doing some hard code changes, please make sure it will not be overwritten by the merge tool. The source of truth is the JSON file and is used by the Merge Tool to load the initial data.