Default path of replays:
C:\Users\<whatever>\Documents\my games\company of heroes 2\playback
Simply upload the replay file from that folder (which you would save ingame after the match, otherwise there' just the temp file of your most recent game.)
Upload to here: https://www.coh2.org/replay
Replays you download from there you would put into that same replay directory. Put them in there and they should appear ingame for you to watch.
Mind you, replays of old patches don't work.
thanks a ton for that, which interface should I use to watch replays uploaded to coh2.org? I have vlc, but when I go to watch them it comes up with a blank screen.