How do I get all 3 characters together for the "Three man army" trophy?

How to get three characters together

Before you can do this you must complete the story mission "Friends Reunited" to be able to have all 3 characters hang out together. After that you can call the other two characters via the "Contacts" icon in the in-game mobile phone.

Make sure you call both other characters immediately before picking them up, because if you pick one up first before you call the other then you will get a "busy" tone on your phone.

Being able to get "Three man army" trophy even at final mission or after

"[MISSABLE] This trophy can be missed if you have not unlocked it by the time you get to the final mission. Make sure you choose "Option C" when offered the choice, after which this trophy is no longer missable."

According to the following link and the above text you should still be able to obtain the trophy.

http://www.ps3trophies.org/game/grand-theft-auto-v/trophy/68567-Three-Man-Army-.html

If you didn't get the trophy before the final mission, and choose option A or B, then you're not longer able to do it.

Play up to the mission where you steal Madrazo's wife. Then, Trevor and Michael will be together so go as Franklin and travel to Sandy Shores. Just remember this just gets you all together not able to do activities.