Tourist to Work Visa change length?

I'm currently on a Tourist Visa until November and have recently received my Certificate of Eligibility to work under the Specialist in Humanities category of visa status. I now have 2 options: one is to leave the country and apply for a Work Visa at a Japanese embassy abroad, or to apply for a Change of Visa Status at the Tokyo Immigration Office. I have called the office to ask details about the length of this process but they say they have no idea. From what I've read online, applying for a work visa at a Japanese embassy in another country can take up to only a week or so, but I'm really short on money and would prefer to stay in Japan to complete the process. Does anyone know how long the process to apply for a Change of Visa Status from a Tourist Visa to a Work Visa can take? On average? Another issue is that I'd be unable to leave the country during the application process to change from tourist to work visa and if it takes several months it would be very troublesome. Are there any answers out there? Please help...

With you being a tourist and all with no commitments during the day, why don't you just go to the immigration office wait in line and try to apply. You will get a better answer there in person reather then over the phone. You have nothing to lose. I shouldn't imagine it would take several months to process. You might be able to extend your tourist visa within Japan depending on where you come from. So just go.

The in-country visa process usually takes a couple of weeks to a month or so at the most.