|N version||1.3 and later|
Method 1 (NEHS)
From the start, there are two ways to go, both very perilous. The first way is to jump on the fragment above the up thwump, jump to the left wall, and let the left thwump activate above you, then wallclimb and walljump into the main ruin. The other one is also hard: go right, past the up thwump, then jump and land on the ledge in-between the two mines, then jump into the main ruin.
Either way you go, after you enter the main ruin, you've got a hard job to do. Flip the first switch (closest to the start), then land on the left fragment's wall. Jump onto it. Then, leap and flip the second switch, but stay away from the mine below! Head right, avoiding the drones and the mines, and flip the third switch (closest to the bottom right). Jump up to the fragment to the left of it, and jump up and up again, to flip the final switch. Then, maneuver through the fragments, and get into the terminal area, without incident. Evade the zap drone, then activate the terminal. Get down, through the fragments, and onto the ledge by the exit structure. Be careful here, or else you'll need to repeat the entire level. Wait for the zap drone to come up from the exit, then jump over the half-wall, and into the niche. Avoid the zap drone, wait for it to come up again, then run and land in the exit shaft before the zap drone comes back.
Life247: I found out that there is an easier way to start. First jump on/over the thwump stop, jump into the space above the first mine to your right. Stop when you hit the wall but DON'T wallslide. Fall into the space under you, and FULL jump over the mine. Now you can continue the other tutorial.