Renewal of HK passport in New York

Hello there,
I am going to renew my HK passport in NYC. But I am very confused with the procedure and fee. Here are my questions

1. I know I need to pay for the passport fee + handling charge to Consulate office. Shall I make it separate payment? For example the passport fee in a cheque to HKSAR Government, while the handling charge will be pay directly to Consulate office?

2. Do the Consulate office accept the handling charge in cash? Or I need to make another cheque or money order?

3. Do I need to make an advance appointment?

Thanks much.
Jennifer