On a scale of one to super hard, how hard would it be to change Damus into a web client?

Iris is both an Android app and a web client, while Plebstr is an Android app, with web client access "Coming Soon" according to their official site.

So, I am presuming, they are changing their Android app client into a web browser-based client.

(However, I may be ENTIRELY wrong, and the more accurate description might be "REBUILDING their client (from scratch) as a web browser-based client.")