Despite lying 11th in the Aviva Premiership, Worcester's defensive record is currently bettered by only three clubs this season - leaders Harlequins, second-placed Saracens and Northampton.
"We have put a huge emphasis on defence since the start of the season with Phil Larder coming in as a specialist defence coach, and it has paid dividends in the games," said Hill. "What we are going to do now is change the focus for these next couple of weeks and really put a massive focus on the attack and try and get that part of the game really spot-on."
He added: "We have tweaked a little bit of strategy, but also concentrated on lifting the intensity up in attack.
"If we can match the intensity that we show in defence with our attack, then we are going to be strong over the next few weeks. We have got to be at them from the start."
Hill has made four changes from the team narrowly beaten at home by Wasps last time out, handing starts to full-back Chris Pennell, wing Tom Arscott, prop Oliver Tomasczyk and flanker Matt Kvesic.
Stade, meanwhile, will be led by Italy captain Sergio Parisse - the starting XV also includes England internationals Paul Sackey and Tom Palmer, plus Argentina's World Cup skipper Felipe Contepomi - with the Parisians looking to go one better than last season after finishing as Challenge Cup runners-up behind Quins.
Elsewhere on Thursday, Toulon - minus a rested Jonny Wilkinson - begin their Pool Two programme against Italian side Petrarca, but not on anticipated home territory.
Poor weather in the south of France has rendered Toulon's Stade Felix-Mayol pitch unplayable, so the encounter has been switched to Stade Pierre Rajon in Bourgoin.