Eligibility is: have you paid your money to sit the exam? Yes - your eligible. No - your not eligible.
Basically, to sit an exam, you just need to purchase it on the prometric website (click "Schedule Now" on this page: www.microsoft.com/.../exam-70-480.aspx).
The 1 year of experience is a recommendation for the exams, but is not compulsory or enforced. I sat the 480 exam shortly after completing my bachelors degree. I did not have a job at the time and have never worked as a developer.
Hope that helps.