How do you change a 22R to a 22RE?

To convert a 22R engine to a 22RE, you'll need to replace the carburetor with a fuel injection system, which includes the intake manifold, fuel injectors, and throttle body. Additionally, you'll need to install the ECU (engine control unit) specific to the 22RE, as well as the wiring harness to connect the components. Ensure that you also adapt the fuel system to accommodate the higher pressure required for fuel injection. Finally, make any necessary adjustments to the exhaust system to fit the new intake configuration.