Edit existing custom fields

Edit existing custom fields

I just made a custom field, but I want to edit it again; For example I want to change the name. Can I do this?Or do I need to drag and drop it in the 'deleted'fields and make a totally new one?

Furthermore I need to put in values for the cuisines:
So I need a picklist which includes:
European
Asian
Italian
Chinese etc.

How do I do this?