I don't think you will get much help for DRM removal on the Digital Edition forum.
You won't be able to make any changes using ADE prior to DRM removal.
After DRM removal you will have a standard .epub or .pdf.
There are several DRM removal tools, I don't know how similar the result are: try EPUBEE.
For a .epub you can massage details such as fonts in Calibre.
If you are more technical, you can open the .epub using a zip manager such as 7-zip and see all the files.
You can then edit the .css files, and any font files that may be embedded, or even the individual .html files if easier.