How would the ancient aliens leave an instruction manual
In the future humans have used generational ships to explore the galaxy. It's taken centuries but we have finally found several habitable planets (they are not without their challenges of course).
On one such planet we discover a great machine, essentially a giant cylinder in the ground. The 'walls' are 100 meters thick and packed with machinery and what appear to be control rooms. It is clearly very old, the best guess is 50,000 Earth years but it's impossible to say for sure. The hallways and ramps were made for creatures of roughly similar size to ourselves, with ceilings around 5 meters high. 302
There are some remnants of a civilization on the surface - tunnels, worked stone, channels in straight lines, etc - but nothing that provides any real clues as to who they were.
We conclude that some rooms are control rooms because they have flat sections on the walls and sliding panels with a rippled texture that seems to respond to touch - no buttons or knobs as we know it but they do seem to be some sort of input device.
For the purposes of the story, the ancient aliens wanted future civilizations to have access to this device. The question is, how would they leave instructions for working this incredibly complex machine such that any type of life form would be able to understand it in the far future?
My assumptions about the aliens:
* Roughly our size based on the Earth-like gravity of the planet, say between 1-3 meters tall.
* They evolved a way to physically manipulate tools with precision
* They have senses to detect and interpret light and sound
* Highly advanced technology with the ability to generate large amounts of energy and the ability to produce any material that we (humans) know of
* They have explored large portions of the galaxy
* They were aware of other life forms that evolved on various planets and could identify general common traits among these
As a bit of background, the device is used to fold space, allowing for instantaneous travel. The aliens used a type of Dyson swarm to capture energy and had incredibly advanced methods for storing this energy. The machine is fully intact and has access to stored energy to operate, also intact.
For the purpose of this question please assume that the science behind the generation ships, the space-folding device, habitable planets, and the Dyson swarm are all explained in the story. It is OK if your answer requires additional assumptions about the ancient aliens, their specific traits are not relevant to the story, merely the fact that they existed and left this device for us to find.
Note: I found some similar questions, like https://worldbuilding.stackexchange.com/questions/105852/how-could-an-ancient-race-warn-the-future-in-a-universally-understandable-way discussing leaving messages over long periods of time but I don't think it quite matches what I'm looking for. Apologies if it's too similar. 209