You can earn perk points through Challenges, Prepper Stashes, Perk Magazines and the Arcade Mode. You need a total of 292 perk points for ALL
upgrades. In this solution I will show how you can easily get most of them.
In the challenges, you should only do the simple ones like kill xx with weapon x or fly 5000 meter with the wingsuit (achievement) BUT you should during your playthrough attention to the Hunting and Fishingsection in the challenges because there is an achievement for all of them.
Another way to earn a lot of perk points are Prepper Stashes. Prepper Stashes are small treasure hunts. Prepper Stashes are marked on your map with a green diamant after you know the location. You can find a prepper stash by yourself or by talking with people who also has a green diamond over his head. For three completed Prepper Stashes you will earn an achievement too (In this solution are all 28 Prepper Stashes locations / solutions with over 80! Perk Points)
The Scavenger achievement in Far Cry 5 worth 11 pointsFollow the clues to the end of 3 treasure hunts (Solo Campaign only).
As you discover the world of Far Cry 5, you may notice there are Perk Magazines in the open world. Each Perk Magazines grants you one Perk Point. I create a video for each region with a lot of locations. If you collect all Perk magazines from the videos, you will earn another 77 Perk Points.
Jacob's Region - 20 Perk Points
Faith's Region - 32 Perk Points
John's Region - 25 Perk Points
Together with all Prepper Stashes (81) and the Magazines (77) you have already 158 Perk Points and with the Hunting / Fishing / easy Perk Points from the Challenges you should more as enough perk points to get this achievement.
PS: It is possible to get all perk upgrades.