Go to:
Safer Skies Through Education - FAA - FAASTeam - FAASafety.gov and register. I do my heavy training/checks with a govt agency and use the paperwork as credit towards a phase to earn my flight review (again, it isn't called a Biennial Flight Review anymore, just Flight Review). Its all very straight forward and easy, and fully described on the website.
If you have a CFI, the online renewal courses every two years can also be used as part of the credit towards completion of a phase. Basically, log everything you do and the system will tell you what more you need towards completion.