In most cases eDrawings files cannot be converted to anything else, simply because they are used as previews and for printing - not for further editing. Somewhat similar to PDFs in their use, but used for CAD designs. Some .easm files might have been exported with the option 'allow save' which apparently allow for some basic export to other formats, for example STL.
It is likely that you have to obtain the original SolidWorks models, as options for easm to step conversion are pretty limited.Open EASM file Open STEP file
A 2D and 3D CAD construction software