Pelaav Research Station
This quest starts during the quest "A Trail of Hope", immediately after you leave Aya for the first time. It’s one of the two tasks Jaal offers you as a means to earn Evfra’s trust, and if you instead go after the quest(s) on Voeld (as suggested by this guide), this quest will subsequently be demoted from a "Priority Ops" quest to a "Heleus Assignment - Havarl" quest. Many of Havarl’s quests (including the quest "A Dying Planet", which will task you with getting Havarl’s vault operating correctly) require you to finish off this quest, first, so it’s a fine place to start.
From where the Tempest lands, continue east to find the Pelaav Research Station, inside of which you’ll find Kiiran Dals. Depending on when you start this quest, her reception will vary, but the outcome is the same; she’ll tell you about some of her scientists who were meddling with Remnant tech and paid the price. Fiddling with the Remnant seems to be a shot in the dark for everybody but Ryder, and frankly, the Angara are fortunate to only be stuck in stasis.
The Southern Monolith
After you’re done chatting with Kiiran Dals, the quest will update and you can explore the research station to loot the odd container, chat with some Angarans (Raashel Vier will start the quest "Forgotten Stars") read some Datapads and perhaps a Communications Terminal, then head outside and venture north to claim your first Forward Station. Your destination is a Remnant monolith to the southeast, but you might as well discover a few things along the way. Head head and slightly south until you reach another Forward Station, then turn east and climb up some Remnant pillars to find an Adaptive Remnant Core Device. Scan it for some lovely Research Data points, then return to the Forward Station and head north to find a Mineral Cache. You’ll probably find a number of these containers across Havarl, and they’re noteworthy for containing a good bit of Titanium, if nothing else.
Turn south from the Forward Station and head down into the jungle, where you’ll find several Roekaar, likely including Raiders, a Saboteur and a Sharpshooter - the three types of Roekaar fighters. Fight your way past them and through a Remnant doorway to the south. Continue south down a ramp through the Remnant structure you find yourself in and note the Remnant prowling around. They’re not immediately hostile, but if you get too close, that’ll change, so pick a fight from an advantageous position and destroy them - they include Assemblers, Observers and a Nullifier.
Once the Remnant are dismantled, loot them and the chamber they were in to find the odd container and Nickel node. Most interestingly, however, be sure to search the eastern wall near the ramps to the north, as along a rocky shelf, just under a bioluminescent mushroom, you’ll find an odd bit of fungus. This fungus can apparently be distilled into alcohol, and thus is of interest to the bartender back on the Nexus. Scan it to advance the quest "Task: Better Crafting".
Scientists in Stasis
When you’re done messing around in the first chamber, continue south up some ramps and go through another doorway to reach the Remnant Console, around which three Angarans are stuck in stasis. Scan them if you want to confirm that they are, in fact, alive, then note that there’s another Remnant puzzle on the console here. You know the drill, scan the ground to locate some conduits, then follow them to their glyphs; one can be found on the wall to the southeast and another awaits on some stonework to the west. While you’ve got your scanner out, be sure to scan another Adaptive Remnant Core Device off a ledge to the west, and search around off the ledges to the west and east to find containers and Nickel to plunder. Don’t worry - those Angarans aren’t going anywhere. When you’re done looting and have scanned both glyphs, return to the Remnant Console and solve the Sudoku puzzle (solution provided).
After the puzzle is solved, the confused Angaran scientists will thank you, then wander off. Job well done, team! If Jaal is with you, he’ll advise you to return to the Pelaav Research Station, which is well worth heeding. Return to Kiiran Dals and you’ll hear her and her assistant talking about "gray spiky aliens", after which Jaal will make a perhaps out-dated reference to Evfra and earning his trust. Once this conversation ends, so will the quest, earning you 29 AVP, 2% Havarl viability and 270 XP. It also plants the seeds of new quests, updating "Turian Ark: Not Dead Yet" and starting the quest "A Dying Planet", the latter of which will earn you most of the viability you can gain on Havarl.
That being the case "A Dying Planet" should be a priority, as numerous other quests can be completed while traveling about in service to the numerous objectives of "A Dying Planet". On the other hand, you can investigate the Turian presence on Havarl along the way, so be sure to talk to both Kiiran Dals and Assistant Torvar to advance these quests.