The TC is equipped with a reset button .. it does 3 different kinds of reset.
Use soft reset.. ie press reset for any time between 1-5sec.. (apple says 1sec but difficult to time that).
That will change all the passwords to default. Go into the TC and change whatever you want .. you have about 4min to do it.
I have no idea what password you need.
There are at least 3 different ones.
TC administrator password.
And there also could be user passwords.