Is there a way to change Permalinks settings without access to Permalinks page?

I’m working on a friend’s site for them. Since yesterday I can’t make a new page (I get taken to a blank white screen when I try) or access the permalinks page (it takes me to a page with the dashboard interface there but there’s no content on the page).

This problem coincides with a change my friend had me make, which was to make blog posts’s url’s not contain the date before the blog post titles. Apparently this is bad and causes slowdown. I could easily change it back, but like I said I can’t access the Permalinks page.

Is there a way to go into database or tables or whatever for WordPress and change it back to how it was? I could probably figure out how to do it if someone tells me what I’m looking for.