Hii Imran ,
This might be helpful
Backup your XLF file
Rename your XLF file to a ZIP file
Open the ZIP file and copy document.xml to your file system
Edit the XML file and update the following tag; version=”x.x” for the version you want to revert to.
In my instance I am updating it from 6.0 to 5.3.1 as I am using Xcelsius 2008 SP3 FP5
Copy document.xml back into the ZIP file
Rename the ZIP file back to a XLF file
Regards
Jeetan