Open Question: How to lower blood pressure in matter of hours?

I am going to go get the MEPS military physical and i know with me being stressed there i WILL have over 140/90 BP and will disqualify.... i was wondering if i was to eat something or chug a buncha water ( lets say a few liters within a hour) would it drop my blood pressure greatly?? lets say 6-8 points?? i seem to be running around 136/83 average idk why... i excerise and am skinny