1. Share it over SMB just like any other printer on your server.
2. It's important to use your servers netbios\hostname \\SERVERNAME\Dymo instead of the servers IP \\192.168.123.123\Dymo - Source
3. Kill all Dymo .exe files you can find in tasklist. Seems like one of them prevents yout list updating.

I've running both DYMO LabelWriter 450 & DYMO LabelMananger PnP using this using software version DYMO Label v8.5.1.181