You're going to have to get under it while on a lift or jacked up and inspect the exhaust to see where it failed. You can get pre-bent, cut to length, bolt on pipes, muffler, catalytic converter, at places like Auto Zone then you may need to either expand the pipes as needed or pay a ~muffler shop a small amount to do it for you.
Whether it's worth it depends on how much you're liking the vehicle. Parts + DIY labor should end up under $200 if you can get some coupon codes to work at Advance Auto Parts or if some of it is salvageable which is likely, though I don't know if yours has dual pipes and cats which could raise the cost. Having a shop (non-dealer) do it, I'd expect it to run closer to $500, or less if there's less damage. It may have only failed in one area and be under $100 to DIY. It might be as cheap to get the parts off Rock Auto's website.
As for how, if you get the pre-bend, ready to install pipes then you just take the bolts out, take it off the hangers, and may need a hacksaw, angle grinder, or whatever is convenient to cut somewhere. Measure twice before cutting anything. Expand pipes, slip (beat) it together, put clamps on joints. If you're into welding there's another option but welding before putting it on "could" be tricky or impossible if the vehicle isn't on a lift. Keep in mind that if you end up with fuel in the exhaust from running it again, then sparks from cutting could be a problem. However I'd expect you'd want to wait a while, at least for it to cool down before working on the exhaust.
