It is now much easier to take the PRINCe2 exams in Nigeria. APMG offers exams through British Council office in Nigeria in a few cities. I did my PRINCE2 through PRINCE2 eLearning with the company called Knowledge Train, and as far as I know, they offer the bundle in Nigeria as well which include exam vouchers that you can use to book your PRINCE2 exam in Nigeria. If you need more info, feel free to contact me. Their website is http://www.knowledgetrain.co.uk

Cheers,
Jay