After some search i found it! Sadly its not subbed... yet.
here's download link(ofc not mine:p)
http://www.megaupload.com/?d=I3JDYM25or if you want to watch it online:
http://www.anidragon.net/Also one more thing i have found(maybe everyone knows about it already xD), is that there gonna be alternate epilogue added too.
"one more ending that no one knows" will serve as an alternate last segment for the final episode of the anime, which aired on June 25. The epilogue will be included in the final home video volume for the anime.
The Neowing retail website had revealed in June that the seventh and final Blu-ray Disc/DVD volume will ship with the 13th television episode ("Graduation") and unaired special footage on December 22.
[Via Livedoor, Uri-Sure Matome R]
According to Dengeki G's Magazine, Angel Beats! Blu-ray and DVD volume 7 will carry an extra anime "Another Epilogue". It's a different version of the epilogue in the Episode 13.
Source: Scan of Dengeki G's