How do I get into the Fens monastery?

Hint 1 of 8:

Have you looked through the monk's possessions yet?

Hint 2 of 8:

There is a nice way to call for help.

Hint 3 of 8:

Blow on the whistle and a boat will come.

Hint 4 of 8:

You're supposed to give the guard-monk two tokens.

Hint 5 of 8:

Those tokens came from the monk that you fought.

Hint 6 of 8:

First of all, give him the whistle.