Remove WordPress.com jetpack connected sites no longer available

I have a few sites that are dead, but the sites still show up in my wordpress.com dashboard. How do I remove WordPress.com Jetpack connected self-hosted sites no longer available, most of the sites are dead and long gone.

http://gard7.sytes.net/
http://barnsbehov.kenthhagstrom.se/
http://stage.geologiskamuseet.se/ (not dead, but shouldn’t be connected to my account)
http://foto.kenthhagstrom.se
http://nordicwp.com
http://zilver.kenthhagstrom.se

IMHO there should be an option to do this in the wordpress.com dashboard, I’ve looked there but I haven’t found anything to accomplish this.