Ick, I hate this kind of twaddle.
"If it is to be..." = If "it" is going to happen. "It" presumably meaning success, progress, a hundred percent increase in sales over the next fiscal year, whatever the stated (or perhaps unstated) goal is.
"it is up to me" = rhymes with "to be." I'm serious. Overall, this motto is exhorting everyone to get off their butts and work. Don't wait for somebody else to do it - pitch in and do it yourself, if it needs doing. The plunger was introduced because plunging a clogged toilet is an unpleasant job - the boss is demonstrating that he's not afraid to tackle even the most unpleasant jobs, and the sales force shouldn't be, either.
In other words, "there is no I in t-e-a-m."