I assume you have the yarn in balls? If so, you might want to make hanks out of them (by wrapping them around a chair top). Then tie the hanks so that they can't come undone (using scraps of washable yarn). After you've secured the yarn, you can wash it to get the kinks out.
This site is about how to salvage yarn from a thrift store sweater, but the same idea applies for the washing part of it (scroll down to find info about this method): http://www.weebleknits.net/thrifty.html