locating the firecut off switch under the bonnet of renault kangoo van?

ive reasonly bought a reno kangoo van ,had a few probs starting it so a bought a new battery and new heater plugs,still wont start ,my friend tells me there is a fire cut of switch under bonnet that i might of lent on by accident,where can i locate it and how do i take it of thanx the van in question is a renault kangoo van diesal 1500

craig kirk
September 2011