Hmmm. Not quite as simple as just pulling the old one out and putting the replacement in. All the controls and the ECU would need to be installed too. This is tied to the speedo so that would be part of the change out. Also, these are a bit more electrical load, so the charging system might need upgrading depending on the stator that is in the replacement engine.
The stuff above is NOT an exhaustive list. Lots to consider.
Why are you considering this? If you are just looking for a FI bike, then it would probably be way simpler to just sell the carb bike and buy an FI bike. Or do you want to do it as a project?
Cheers,
TQ