Easy drive - Yes. As PP said just go up I75 to I4 East. If you miss the multiple signs for WDW then you have problems I just can't help you with.
I would say that it's about 3-3.5 hours to get from Fort Myers to WDW, might take you about 15 minutes just to get to 75 depending on how close to the beach you are. Not a lot of things to look at, but a pretty easy drive to make.