In The Store Where You Fight Against Cliff - Crisplins - Get A Propane Cyclinder And Throw A Few All Over The Place. Make Sure You Take A Gun Preferably A Pistol Or Shotgun. When Cliff Gets Near To The Propane Tank(s) Shoot Them This Will Significantly Damage Him If Not Kill Him. Also Another Rather Easy Way To Defeat Him Is By Using The Shears. Get Close To Him And Keep Attacking Him With It, He Dies Really Easy That Way But Be Careful Because He Hits You Quite A Bit During This One.