Wow, yous guys on the coast gets all the fancy stuff first. Out here in the desert we can get Cable broadband OR DSL broadband, but yous guys get both wid "DSL Cable".
Before you break it, go to the Router's config util by setting your browser to
http://192.168.0.1 (typical of NetGear - check your Netgear user manual), go to the basic settings and remind yourself if you are currently using DHCP (which is typical of Cable ISPs) or PPPoE (typical of DSL ISPs) or a static IP (usually costing extra) to connect to your ISP. If using PPPoE note what your account name is. (It probably won't tell you what the password is, so you'll need to look that up.) If using a static IP, note what the IP is, what the netmask is, what the router is, and what the DNS server address(es) is(are). Maybe use Grab to take a couple of screenshots of the router config so you dont forget.
Then, in OS X, open Network Preferences, set the "Location:" pull-down to "New Location...", give it a name like "Direct to DSLCable". Then set the Location pull-down to that new location (this way your old router settings are preserved so you can go back to them).
Set the "Show:" to Built-in Ethernet and either set the "Configure:" pull-down to "Using DHCP" if your ISP uses DHCP, (or "manually" if you have a Static IP) or go to the PPPoE tab and check "Connect using PPPoE" (if your ISP uses PPPoE).
If DHCP, you are done.
If PPPoE, enter your account name and password.
If static IP, enter the IP, the netmask and DNS server addresses just like the router had.
To set it back to using the router you can just switch back to the old Location, or read the router's manual again.