Complex sentence: For instance, the songs "Six Pack" and "Damaged I", which are most known for being released on Damaged, were previously released (as alternate versions) on their third EP and first single respectively.
Split into simpler sentences: For instance, the most famous versions of the songs "Six Pack" and "Damaged I", are on Damaged. However, they were both previously released (as alternate versions) on their third EP and first single respectively.