How to add country as a field in lead object and be able to edit/update the field values ?

Question :

**This post was created as part of a How to Service Request (SR)

Release: 

22A

Summary of the question:

In lead module we need to add "country" as a field. There is one standard field "country" in lead object ..we are able to add that but we can't edit/update the field values(like add /remove country names as per our requirement). Can you please suggest if there is any way to achieve this?

Supporting Documents if any:

None