Cutting down a resume for a job you are over qualified for

So the job market is crap, as everyone knows. Between hiring freezes and the mass layoffs with thousands of people applying to the same position, it's been hard to even get interviews, even with custom tailoring of my resume to jobs. I have been out of a job for 8 months, emergency fund is running low (got another couple months till I have to dig into my long term savings) companies are very slow with interviews in the rare situation I get one, where it can be over a month before I hear back.

My field is biotech/pharmaceuticals. I have a master's in biomedical engineering and 4 years experience in the field, but at this point I need income, and will take anything, whether it's retail, customer service, warehouse work or custodial work. These jobs are looking for people with high school diplomas. Because the credentials they are looking for are so minimal, how do I cut down my resume such that I am not glossed over for being over qualified and likely to leave? Removing all the field-specific jargon, and talking about the experience that mirrors the role gives me like a quarter to half a page of material to work with. I took out the master's degree, left the bachelor's.

What exactly would a job where a high school diploma is the only requirement want on a resume?