HOW DO I PUT REPLAYS ON TORIBASH?

Simple , go advance , click the clip button (attach file) browse the .rpl file , and close the window
? ? ? ?
Profit !

^Exactly what he said, but after browsing for the file make sure to click upload before closing the window. lol

If you're trying to watch other people's replays, download the file and open it with toribash or put it in your replays folder and open it in the replays menu. If you're trying to upload replays, check these links.
http://forum.toribash.com/replay.php
http://forum.toribash.com/showthread.php?t=214197

how do i post replays on DC of clans. (sorry if its a stuipid question.) and is it the same as posting replays

Posting replays is the same anywhere on the forums.
So yes.
Use the link that Fish provided you with (http://forum.toribash.com/showthread.php?t=214197) if you still need some clarification on uploading replays to your post.

Thank you

How do i exchange the host fight player?

What do you mean?