"We can't give away penalties in our half because it is almost guaranteed to be three points," said Clermont's Byrne. "We will have to be squeaky clean.
"However, Toulon are full of international players so it is going to be difficult. We've played them twice this season, we beat them the first time game at home and drew the second one away.
"You hear stories that the French title is more important but everybody wants the Heineken Cup just as much.
"It's massive, especially after losing last year in the semis. We sat down as a group and it surprised me how much the French boys want to win Europe. We want to be the best team in Europe not just in France."
On the individual front Byrne is aiming to become only the ninth Welshman to win the Heineken Cup.
"It's not many Welshman who have managed that," said Byrne. "It would be nice to get into that prestigious club but we'll have to wait and see.
"It is difficult for a Welsh region to win in Europe. The main thing is having strong squads and in Wales maybe the depth is not there."