Sorry for the late response. I've seen your question only today.
1. A furniture library or a texture library is basically zip archives.
2. So, you have to change the extension .zip to .sh3f or .sh3t
3. Starting with version 1.5.3 I've made a bash script Create2DSymbols.sh to simplify this process under linux which is inside the package.
4. While it's not quite that simple I could made it for you like I've already done for others fiends here.