Filng of roc returns

i am new to ROC work, i have two questions,

1) does form 23b required to be filed everytime (eventhough) practically same auditor continues? if yes then do we need to take fresh appointment letter from company?

2) how can we file roc returns (23ac, 23aca, 20b, 66) for the company if we do not know the login id and password? can it be reset or reacquired. (earlier we use to outsource the work, the login id and password is with them, it would be akward to ask them for the same)