Yes you can, you can import eagle file of device you have downloaded at SamacSys ![enter image description here][1] [1]: /editor/20170720/597026dce7102.png

I have now successfully imported a component via Eagle, however when I try to convert it to PCB I get "Package is not assigned, please assign a package". How do I do this ?

This is how to do it for a symbol placed into a PCB: https://easyeda.com/forum/topic/How_to_assign_or_change_the_PCB_footprint_assigned_to_a_schematic_symbol_and_then_update_them_in_the_PCB-1SoiAuM4Y To do it for a symbol in `My Parts` (or cloned from any SHIFT+F search or after saving an edited symbol opened by double-clicking on any symbol in the left hand EELib panel), open the symbol for editing and click in the `package` text field under `Custom Attributes` in the right hand panel.

Sorry, that should have started: `This is how to assign a PCB footprint to a symbol placed into a Schematic:`