The Remnant Decryption Terminal is underground. But before you go there, two Glyphs can be found at ground level. A pillar from the underground structure is sticking out of the snow. Glyph 1 & 2 can be found there.
Location: Between the monolith and the close by the small remnant structure.
Glyphs 1 & 2
Then go underground and get the 3rd Glyph at the foot of one of the pillars. Scan and follow the yellow cables.
Glyph 3, underground
Now use the terminal to solve the puzzle
Monolyth 2
The 3 Glyphs are on top of the pillars. Close to each other.
Glyph 1
Glyphs 2 & 3
Now use the terminal to solve the puzzle
Monolyth 3
The Remnant Decryption Terminal and the Glyphs are all underground. Follow the frozen river inside.
Glyph 1 is at ground level. For Glyphs 2 &3 you need to jump on the remnant pillars and then onto the long structure. Walk to the tip of it and scan the Glyphs at the end.
Glyph 1
Glyphs 2 & 3
Now use the terminal to solve the puzzle
Vault
Head to the Vault. Be quick and activate the interface inside to get the Protection Bubbles up. Otherwise you freeze to death. Move from bubble to bubble to get along safely in the vault. Next, open the big vault door with another interface, that sends a laser light towards the door.
There is another Interface. Activate it and jump on the pillars to get to the left.
Use the Lasers and the interfaces to get the light: