Use the command

 git clone https://github.com/metno/noresm 

If you get error messages, verify that you can open the page https://github.com/metno/noresm in a web-browser. If you can not, you are probably not a github-user or not member of the noresm group on github. Send email to alf.grini@met.no (with a copy to trond.iversen@met.no) to get the right permissions. (You can create the github user yourself)