That's rather a large jump in versions, and there's some hiccups.
The best thing you can do is plan for doing at least two phases as the absolute minimum you should to is to take 2.10 to 3.5 and then 3.5 to 5.x - it's really not funny trying to upgrade 3.4 or below to 4 or 5 without going to 3.5 first.
Basic principles though:
More and more people are building their careers with Atlassian, and we want you to be at the front of this wave! Important Dates Start the Certification Prep Course by 2 April 2019 Take your e...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs