SV Kament for OT Surfdev

Hey everebody!

I've got some trouble with installing another comment plagin(module) on OT Surfdev theme.
For example, i need to install sv-kament\disquss comments system and nothing appear on my site.
I go to the extensions - module-download-install-activate (all needed things)than save - F5 - and nothing happens.
What i do wrong? another words, would you be so kindly to advise me where i can switch off standart comment system and install another one instead switched?

Looking for your replies. this is very need for me.

thanks.