Depending on the level of the courses you need you might want to consider taking them from a community college. I was missing one required prerequisite course when I was applying to graduate school and I took it at my local community college. There wasn't much of an application process; rather just giving them my information, sending a transcript, and then the payment for the course. The entire process took approximately two weeks. Just make sure the school is accredited and that the course covers the type of information/material you will need. Good Luck!