To some degree, the success of headlight restoration depends on what kind of problems you're experiencing. For example, if your lights weren't as bright as they once were then a good clean up will do wonders. However, if you're expecting to replicate the performance and brightness of modern xenon bulbs then you'll likely end up disappointed. Various kits are available, I'd start by inspecting your lights and identifying what issues you're facing and then decide on a suitable kit.