Network Help

I was recently given a Netgear Home Network Gateway CGD24N v2 by my internet provider to replace the then used Motorola Surfboard SBG 900.

I have generally always had low internet signal from my computer (and i still do now with the new Gateway) to the Modem due to distance.

What i was hoping to do is use the motorola surfboard and plug it in to another wall socket closer to my computer. So in theory, Computer > Motorola Surfboard > Netgrear Home Network Gateway > Internet.

I did put the surfboard in the socket and its on working fine and i can connect to it from my computer. The problem is although i can connect from my computer to it i don't know how to do the next step. getting the surfboard to connect to the Netgear home gateway.

I'm not great with internet connectivity/networking so a long guide would be great. Thanks in advance for any help.