Here's a method I came up with using Calibre, on all platforms where it's supported.

1. Install the DeACSM and DeDRM plugins into Calibre
2. In the plugin preferences, configure DeACSM and set up anonymous authorization, then export the encryption key and import it into DeDRM's ADE keys
3. Restart Calibre! This is important!
4. On archive.org, find the book you want to borrow and loan it out
5a. If you can borrow it for two weeks, do that and download it in the format you prefer
5b. If you can only borrow it for an hour or it doesn't give you a download, borrow it anyway, then copy the identifier in the metadata, add it to the following URL: https://archive.org/services/loans/loan/?action=media_url&identifier=<IDENTIFIER GOES HERE>&format=pdf&redirect=1 and download that (you can also change the format to epub or similar but it may not always be available)
6. Add the ACSM file to Calibre and it'll download it and then decrypt it for you
7. Be sure to return the book so other people can use it right away!

Happy reading!