You probably need to wait until December. Then you go on a web site enter your registration number and AFM and print out a form. Take that to the bank or use the payment code to pay using online banking. Haven't got the link with me but I will post it in a couple of weeks. No rush.
I'm hoping to do mine on my bank's (Piraeus) online facility. Online payments-by category-public sector-public services-annual vehicle fees. Fill in AFM and vehicle registration. Then retrieve payment data from Taxisnet. Complete form and pay. I HOPE.
I've not seen any figures quoted yet. I have not seen any reports of them being increased, so probably the same, but we will know for certain when the web site is live for 2018 in a couple of weeks or so.