HEADER TEXT "ownCloud"

Hi, i woud like to delete the “ownCloud” text on header, but i can´t found anything about it, someone can help me ??

Hi,
You need to use a theme to make the changes that you want.
The theme can be simple or as complex as you want to make it.

Look at this on how to create a theme,.
Theming ownCloud :: ownCloud Documentation