How to find your replay.
C:\Users\YOURCOMPNAME\Documents\Heroes of Newerth\game\replays
Take the replay (the replayname is the same name as the match id)
Change the name too - nickname_hero_action_replaytime_matchid
example: widdz_soulstealer_quad_13m_555324
and upload it too:
http://www.file-upload.net/