LTSpice to Autodesk EAGLE
There's two ways to do this in eagle.

In your schematic editor like you said, there's the LTC Spice button. If it doesn't appear for you, right click the top bar and make sure 'Command Texts' is ticked.



If this doesn't work or you don't have that option, then you can run the ULP manually. 

Go to 'File' and select 'Run ULP'. Scroll down until you find the 'LTSpice.ulp' and run this instead. The button on the taskbar is essentially a shortcut to this .ulp file



Edit: As I was last aware this feature only works for Windows. They were working on OSX and Linux being able to import from LTSPICE but I'm not sure if they ever finished it.