New to Docsis 3 and Forceware

Hi know this isnt' the forceware forum but was told I can probably get some help here.
I have a SB5121 running Haxoware. Everything's good I can get on some days maximum speed from it 30 megs

I got this new Docsis 3 motorola modem from Ebay with Forceware. I know Docsis 3 service is in my area because I also have a Docsis 3 modem from the ISP running
I would like to know how to program this to get the maximum speed available
please and thanks
G