You have to log in to the Control Panel with your Hostpoint ID.
Then click in the menu on «Domains» and on «Edit» to access the domain administration.
In this menu you also have the option to set a .ch or .li domain inactive by deleting the registered name servers. This means that the domain can no longer be called up, but remains in your possession until the contract is terminated.
Info: Note: Note that the final change of name servers can take up to 48 hours after the new servers have been entered.