I doubt we can offer much detailed advice since you're clearly Virgin Canada, and this a UK forum for Virgin Media, which uses different technology.
It certainly is often possible to reconfigure old ISP devices as access points, but based on my experience I'd say that it is often a false economy. I have tried it with two different ISP devices one worked erratically with poor wifi, the other was more stable with poor wifi. Much better to bite the bullet and buy a mesh wifi system in my view.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks