Authorize.net – how to edit code in plug in

Hello, is there a tutorial or information on where or how you change the code in the plug in for authorize .net? i have my ids, i just need to know where to plug in my id’s.
example: (‘authorize_loginID xxxxxxxxxx’) or(‘authorize_xxxxxxxx’)
(‘authorize_transactionID xxxxxxxx’) or (‘ authorize_XXxxxxxxxxxx’)

and would you replace the code every time you see (‘ authorize_transactionID’) (‘authorize_loginID’)

thank you very much, Deb