This is the very first Tallneck you’ll encounter. Your jump off point is in the building ruins where the Tallneck is walking around. There’s only a handful of watchers guarding the area so you can easily eliminate them. Make your way to the upper floor and find a spot where you can leap.
The jump-off point is located in the island where the Tallneck is circling. There are some watchers and Snapmaws there so get rid of them first and clear the way. Once the coast is clear, go to any of the high hills of the island and time your jump as the Tallneck passes through.
You have to clear out some of the Cultists around the area. There’s a Corrupter in the middle as well but you don’t need to attack it; just clear the platform where you’ll be jumping off from. If the platform doesn’t have a ramp, it’s probably connected to another platform that has ladders or access ramps. Look for these first to get to the intended platform.
The area where the Tallneck is moving around is full of hostile machines like Watchers, Longlegs, Bellowbacks, and Ravagers. You don’t need to take them all out; however, alarming one of them, especially the watchers, will call in the other machines to your position. To reach the Tallneck, you have to jump off from one of the ramps by the rocky hills. There are several of them in the area clear out the watchers that may compromise your position while attempting to access the jump off point you want.
The jump off point is the rock formation where the tallneck is circling around. Aside from watchers, there are Longlegs on the rock formation itself near the cliffs as well as other hostile machines in the woods around the vicinity. You can use the path leading to the rock formation’s ledges or you can scale the rock wall in the other side of the formation. In any case, find an unobstructed edge and jump from there while the Tallneck is passing through.