said by Smith6612:
Your FiOS TV will still work. The ONT just won't be providing an internet signal via the Coax anymore. So, if you have FiOS TV, take your router and plug it into the RJ45 cabling, and then take the ActionTec you have and hang it off of your DD-WRT router. That way, the ActionTec will act as a NIM100 and can give your STBs information. To make sure though, since the boxes do store quite a bit of guide info in them, unplug the STBs and plug them back in and make sure they download guide data, once you verify that your Ethernet setup is in fact working.
theres a little more than just that, in addition to running CAT5 for the new router he will need to re-route the coax.
1. He will need a coax run FROM the ONT
TO the splitter
2. He will also need coax run FROM the splitter
TO the bridge
(A/T or NIM100)
he may be able to salvage the one length of coax running from the ONT, but he will be running some additional coax for sure.