Rods over time can take a beating, but the first part of the rod that can show wear and tear are the rod guides. The guides are what bring the line onto the rod and then onto the reel and vice versa.
There are a few different ways to replace a broken guide, but the easiest is to pick up a rod guide replacement kit that comes with several size rod guides, glue, and the accessories needed to slip a new guide back into place.
Wrapping thread around the guide and then using epoxy is a great quick fix and will usually hold up.
If you have a big game fishing rod and want the guide replaced right, we suggest you go to a rod builder or tackle shop and have the guide wrapped properly onto the rod.
Check the internet for discounted rod guides and event try going to the exact manufacturer if you take pride in your equipment.