@Woodhound: The ECU upgrade means the ECU is reprogrammed.
The higher power tunes come with a boost valve you need to install. The boost valve has a higher pressure setting (a higher "resistance") than the factory waste gate. This lets the turbo build more pressures.
Anything else are additional components: intake hald down, intake connection kit, the intake tube that replaces the "golden tube"....
Before you remove the ECU, look for some posts on how to open and close the connector. In essence: 1. disconnect the battery. 2. Make sure no zip ties block the connector (lever and slide) to open and move freely. 3. As you lift the lever on the connector, make sure the slide moves freely. Help the slide with one hand as you lift the lever with the other. 4. Pull the connector straight up. Install in reverse order.