Go to the Volcano Island and find this small village, It's the U.S. Base

Then you're going to find this temple, and go inside and do the action at the stand.

Then after you've done step 1,2, go to Boom Island, i recommend fast travel.

Then when you either wingsuit or freefall to the ground, find the Corvette. Then after that you need to destroy the Corvette, i used an airstrike on it.

After the bombing, the boat next to it will drive away.

Now after step 5, you need to go to Le Galera military basei recommend liberating it first, then go to the dock and find the white container.
You need to transport this container to a dock nearby, and somehow lift it up out of the water.

You need to get it into the warehouse, and leave the area, after sometime after you will recieve a message that the radioman is free.

this guide is a fake
you should just play the game instead

My other guide: How to:Console Can someone please tell me how to properly link guides?

okey ♥♥♥♥♥♥♥, this is my guide and its fake
some ♥♥♥♥♥♥♥ decided to copy this and post on some ♥♥♥♥ called "gamepur"
if you dont believe i made first check creation dates

http://www.gamepur.com/guide/21698-just-cause-3-how-free-radioman-di-ravellos-dictatorship.html
thats the web fake guide ♥♥♥♥

NOTE: i contacted gamepur addressing this, and they removed the website.