I have a table like this already.
users
- id
- name
- email
- password
To use the FuelPHP's login system What should I do?
Do I need to write a Custom Driver?
If there is no way you can change these column names, your best bet is to overload the simpleauth driver.
To do so, copy simpleauth.php from Auth/classes/auth/login to app/classes/auth/login, and add it to your app bootstrap (like the example already present).
After this you can modify the copy by changing the fieldnames.