How can i remove the "WPG2" button on header??
Your theme is listing out all the Wordpress Pages, thus why you are seeing a WPG2 Page.. You can rename WPG2 Page to a different name, say Photos if you wanted. I am not sure how to change your Wordpress Theme to exclude WPG2 Page however..
Wordpress / Gallery2 (WPG2) Plugin, , WPG2 Documentation, WPG2 Demo
ok, ths a lot, i try to find out.
And how can I rename that page in the heade? I didn't see that option
You can rename the WPG2 page just like any Wordpress Page, via Wordpress Manage Page. I personally rename mine to Photos..
You can change it on the Manage>Pages tab as noted. There you can also change it to "Unpublished" if you don't want it to show up at all.
I'm my case of I've got 2 buttons show up when I activated WPG2. One says Photos the other says WPG2