Time, patience, and food are usually the best tools for taming any lizard. And you'll need a lot more of the first two. It's a process that will take weeks, likely months, or maybe even years or never. Once the animal has acclimated and is comfortable eating in front of you, you could start offering treats with tongs. If it won't approach the tongs, set the treat in the food dish and back off. Eventually it'll get the idea, and will be more and more willing to approach. Then start working it closer to the cage door, then up onto your hand/arm. Then you can build on that from there.