Remove the dash

I would like to remove the dash between the default entity and the slogan.
Which file I have to edit or where can I find an introduction?

Many thanks in advance!

AFAIK, to avoid any trouble, you should create a new theme for your ownCloud.

https://doc.owncloud.com/server/10.8/developer_manual/core/theming.html#how-to-create-a-new-theme