How do I remove the scrollers in this Document Library?

For the vertical, you could add more web parts in the main part of the page to lengthen the entire page (use the spacer if you don't have any other content). You could also group by a metadata column - if you don't already have something like a 'category' or 'topic' column, you could add and then group by that column with the default setting at collapsed.

For the horizontal, your view needs to show page name only, right now it's adding a scroll bar to show the other columns in view.

Hope that helps!