HTML Editing

Hello all! A friend and I are making a forum using PHPBB2 (Or whatever, it ends in two ) and we came across a little messup. After we made a second nav bar (Using the site description box), we noticed two annoying lines that link to the button that is above them (In this case the Members button).

Hereis a picture of the two lines.

I consulted with somebody and he pointed out the problem. There is one little bit of code I need to take out. The problem is, I can't find where that code is. I've checked the CSS Stylesheet, the website description box, but neither of them have the code I'm looking for.

So my question is, is there a way I can directly edit the entire HTML code for the website, not just small parts. Like if you 'rightclick<view source' and see all that code, is there any way I can get to a sheet or box that has all of that code in it so I can edit it freely?

Thanks in advance for your help!

Go to ACP -> Display -> Templates -> General -> Overall_Header -> (search) {GENERATED_NAV_BAR}

check there