I need to convert a file fromWBFS back to .Iso how can I do this and is there a guide
The backup managers that created the .wbfs file should be able to put it back to an .iso, though it won't be the same as a clean rip from the game disk and still may not work.
When I chose to migrate from WBFS formatted hard drive to FAT32, I used the backup manager to turn every game on the hard drive to an .iso, formatted the disk, then used it to reinstall the games. Most of them worked just fine, but a handful failed and the previously working game stopped working until I deleted it and reripped from the game disk.
So your best bet to get a new .iso file of a game is to get a fresh rip off of the disk.