ordering portfolio items

Hello,
I had someone managing my website but have decided to take over.

How do I change the order of a page that is populated with some portfolio items? I;m pretty sure it is current arranged by date, but is there a way to change that to date modified or better yet someway to “drag and drop” and move around the items? There are quiet a bit of items and they are not in the correct order.

Thanks in advance for any help.