Reordering Groups of Fields on the edit screen

I moved my fields around a bit a while ago but I can't remember how I did it. Would someone please point me to the function/talk that tells me how to do it?

>1 ulmannc: If you mean 'edit book' screen, AFAIK you can't reorder it, but you can customize what is present/absent. Cogwheel icon at the top

If you mean reorder modules on the work page, at the bottom of the right sidebar, 'customize view' or something like that