Dump your EM1s into a folder.
Dump your OS into the same folder. Should be called emaxos.emx no matter what version it is.
If you are confused which version of OS you are looking at use EMXPN to check it.
Open HxC floppy software.
BATCH CONVERT. Select input folder. Select output folder.
Dump the HFEs onto your freshly formatted card.
Make sure you have a config file for the HxC. You can generate one with the software. Or use the one you have in the premade images.
If it doesnt work try a different OS. I had a few different copies of SE and had luck with SE4.0.
HAVE FUN!