Toribash
For me to delete replays (Im on Windows XP)

My Computer >> Local Disk (C Drive) >> Games >> Toribash-3.8 (Depends what your latest version of Toribash you're using) >> replay folder and then delete all your replays you want to delete.

If you need any more help, just mention it here and I'm sure someone will help out more.
Join the [Essence] of Toribash
If you mean on the forum, go to your User CP, Attachements (at the bottom), and simply remove the attachements you want.
Gone