How can I delete duplicate songs from my iTunes library all at once instead of one by one?

I've just changed religions and switched to Mac. As I result I had to convert my music library from WMAs to the apple format but now, I've got like 6000 songs x 2. How do I get rid of the 6000 duplicates?How can I delete duplicate songs from my iTunes library all at once instead of one by one?
There are many softwares for that

try

http://www.easyduplicatefinder.com/



http://www.duplicate-file-detective.com/



http://www.freedownloadscenter.com/Utili鈥?/a>



http://www.moleskinsoft.com/

http://www.al-soft.com/dfd/duplicate-fil鈥?/a>

How can I delete duplicate songs from my iTunes library all at once instead of one by one?
Hold Ctrl and click the songs.