my dad passed away on friday. he has 3 credit cards with balances

Estate debts are paid in a priority.  First, pay all of the expenses of the funeral, pay yourself back and fees you incurred for probate, or anything else, pay the attorney (if you had one) and then I would wait.  It will take some time before the final bills of last illness come in.   Usually the credit card companies will accept some pay down (as low as 1/3 of the actual debt).  Wait until you get further along in admininstering the estate to see what debts are outstanding and what assets are avaliable.