Just buy a wifi router? My father got a tp-link off amazon for $22 shipped, to replace a aging linksys wrt54g and has never been so satisfied over signal strength and reliability before.
Why should they buy a new one?
Why can't they use what they have?
I've seen people reuse the fios routers, but not a DSL router.
But it has a RJ-45 port that can be reconfigured to act as the WAN port...