iTunes: Re-rip songs and keep metadata?

[Traverse]

I have thousands of songs that I've ripped over the years using iTunes' default AAC settings because I never knew any different. Now that I have a nice pair of headphones I would like to re-rip my CDs as Lossless, but don't want to lose years of meta-data and don't want to re-enter all the information.

Is it possible to have iTunes replace the AAC files will Apple Lossless and maintain my current library's metadata? I would need to change the CD info back the the import info wouldn't I?

Thanks.