What do I need to become a registered TAX return agent?

I'm currently studying Diploma of accounting, been working as accounts payable,receivable for companies few years, I have been thinking about work for myself, maybe a small Tax agent that provide some bookkeeping,BAS loging and tax return services for small business, does any one knows what do I need in order to register with ATO as a tax agent? Do I must have Advance Diploma and two years tax experience to apply(heard from friends)? Thanks very much.