.sfv is Simple File Verification, i.e. some kind of CRC that you can use to check your download to make sure that it didn't become partially corrupted, so that doesn't help (I think). .tar is just an archive, it doesn't compress files or anything. Can you look on the site you downloaded it from to see which program they used to compress / split the thing? It'll be kind of hard to guess if none of the files have a real extension. One of them should have a non-numerical extension.