1. Get forms from Imm D. Fill in all forms, including green contracts.
2. Go to Philippines consulate with green contracts for notarization, cost: can't remember, several hundreds.
3. Get back green contracts. Submit all forms to Imm. D. Do this in person and get the visa the same day or drop in the box and return to get visa. (cost: can't remember, about $200?)
4. If maid is not taking annual leave, then Imm. D will usually give 1 year's visa. Before visa expires in 2013, maid must exit HK (to China, macau ok). Will get extra year's chop upon return to HK.
(I think there is no need to provide income proof for renewal with same employer. Also the maid can do all these steps herself)
When I renewed contract with my maid last year, I didn't need to provide income proof. But rules might have changed. Anyway, to avoid the maid knowing your income, put the sensitive documents (ID copy, tax return copy, marriage certificate copy etc) into a sealed envelope and address it to : Director of Immigration, Foreign Domestic Helpers Section. Then the maid will not dare to open it. If the Imm D wants to return any unused copies to you, they will also do it under a sealed envelope.