its easy, but it would be much easier if you translate the French site to understand what you should do. you could use google chrome browser which translate automaticly (i suggest google chrome because it is a bit faster than firefox) or
if You have Firefox: you first of all need the Greasemonkey add-on: https://addons.mozilla.org/en-US/firefox/addon/748
and then install the Gtranslater http://userscripts.org/scripts/show/41049
the rest is easy: go to http://labrute.muxxu.com then click on "se" (logIn) then "sign up" then before inserting you username and password you should change the server by switching the english Flag to the french one. (that is why you created a COM account)
there is no need to insert an E-Mail adress.
then register with your data and accept the terms and thats it
if it did work you should be able to see this
http://labrute.muxxu.com/fight/225450606?chk=74ae just so i would stay on topic