WARNING - DO NOT PLAY ANY OF THE SIDE QUESTS ON CO-OP. PEOPLE HAVE REPORTED THAT THIS WILL GLITCH PROGRESS. IT SEEMS TO BE PEOPLE WHO DO A MIX OF CO-OP AND SOLO WHERE ITS THE ISSUE; TO BE SAFE, ENSURE YOU ONLY PLAY THE 4 SIDE MISSIONS ON SOLO. For those who prefer a written guide, this achievement is for completing Larry's quest line in John's Region. This became available for me about half way through liberating the region.
Larry is a weird but charming enough dude. He's into aliens, and we will help him complete his...personal pilgramage.
There are 4 side-mission we have to complete for this one:
1) Free Larry (Self-Explanatory and easy)
2) The Hero's Journey (Climb the tower, disable the dishes, secure Larry's compound. Easy.)
3) Close Encounters (Collect 4 Alien Pieces. This is probably the most confusing, although still very easy.
In the central crop-circle looking / mowed grass area is one bigger circle and three smaller circles. In one of the smaller circles is some turkeys. Kill them and get
piece 1. Opposite them is a couple enemies in the large circle. Running around will be a dog, chase him until he stops for
piece 2. His "end place" will be by some boxes next to the turkeys, and if you leave this one to last like I did he might already be here.
Then go to the silo with a green top and a blue ladder on it. Climb the smaller silo next to it, jump over, and navigate to the top for
piece 3
The final piece is in the larger circle in the central area. Take out any human enemies, and find it by the cows rear. Note: It's very easy to mistake the final alien piece in "Close Encounters" to be under the cow, as there is another blue patch. This is especially the case if you do them out of this order like I did without a guide. I thought my game had glitched, but this blue piece is NOT one of the ones you need.
PEOPLE WHO REQUESTED THE LOCATION OF WHERE I FOUND THE DOG - 8:48. Where the centre-most yellow icon is, go to where the bale of hay is to the right of it. If he stops running around, thats where I found him.
4) Out of this World - Go to the plant, turn on the generators, return to Larry. Easy.
Once you
you'll unlock your achievement.
If these were your first side-missions (like mine), you'll also unlock the following:

The What Now? achievement in Far Cry 5 worth 23 pointsComplete 3 Side Missions in Hope County (Solo Campaign only).