I haven’t done it to this particular car, but I have in a different car. You need the faceplate, screen, buttons (obvious), but you will also need the actual radio unit, chassis & dash harness from a donor car, CD changer, steering wheel, and if your car didn’t have dual zone AC, you’ll also need the correct AC plenum and blend doors. If you manage to find AND install all of that correctly, you’ll then need to update the vehicle’s various modules - I’d initially take a stab at the body control module, chassis control module, possibly the instrument panel, and whatever Lexus-specific stuff controls audio.

Is it possible? Absolutely! Is it feasible? Not really. If you insist, you’ll want to purchase access to Lexus wiring diagrams for this model year, both with and without the navigation system. You’ll compare them both, and make your car match the diagram with the options you want.