You probably can't.
It may be that some Android devices have the capability of connecting an ereader as USB slave,
and then viewing the ereader storage from some file manager.
In that case, you can probably use it to copy books as well.
Also, if both accept SD cards you may be able to transfer that way.
You won't be able to use it to authorize the ereader; for that you will probably need ADE (digital editions) on PC/Mac.