I made my way through the Aftland ruins and cathedral, and took the lift up to Skyrim. Trouble is, there seems to be no way out of the lift and into Skyrim, since the top of the lift is surrounded by bars. I don't want to have to backtrack my way all the way back through the Aftland ruins, so can anyone help me out?

One thing I noticed is that I got the message "You lack the necessary item" when I activated that dwarven mechanism right in front of the door to the lift when in the cathedral. What is it I needed for that, and was it necessary to be able to exit the top of the lift and into the Skyrim?

Thanks

PS- I haven't been in any other parts of Aftland

Did you try using the lever on the side when you got to the top?

This. There should be a level somewhere once you get out. Activating said lever will lower the bars.

This.

On my very first playthrough on release of Skyrim, I didn't see the lever. I hadn't yet discovered the TES forums either. I ended up fast traveling out. I eventually discovered the lever in another lift, thankfully! Glad the doors stay open after that also.

Edit: as far as the device needed, it may be talking about the Attunement Sphere, but I don't remember for sure.

The Sphere. The doors that stay open are the ones that lead into "a large cavern".