The term "Act of Congress" refers to a law that has been passed by both houses of Congress (the Senate and House of Representatives) and has been signed into law by the President. Full definition
@JamesKPolk Acts of congress can conflict with other acts of congress, that much isn't a problem. (politics.stackexchange.com)
Unfortunately in the Episcopal Church, once you've called someone it takes an act of congress to get rid of them — they can leave anytime they choose, of course (sorry, when «God calls them» somewhere else...) (nakedpastor.com)
Are you only interested in whether the president can unilaterally remove the vice president from office or are you wondering if there other options, such as through an act of congress? (politics.stackexchange.com)