How to use "perform" in a sentence

Sentences

Doing this I deem to be only a simple duty on my part; and I shall perform it so far as practicable, unless my rightful masters, the American people, shall withhold the requisite means, or in some authoritative manner direct the contrary

Nothing had changed, and he decided that he had one last duty to perform: he must send Cosette a final message and tell her of his death