Chelsea overtook Schalke at the top of Champions League Group E by winning 3-0 in Gelsenkirchen two weeks' ago, hitting the Germans on the counter attack.
"We're not here just to sight-see," Boateng said.
"We'll do our best and we'll have to see how it goes.
"We had the first leg and we saw the strength of Chelsea. We're a little bit more experienced now and we know a little bit more about the team. It's going to definitely be a different game."
The former Tottenham and Portsmouth midfielder admitted his time at White Hart Lane was challenging, but he is happy to be playing in England once more.
"Everybody knows that I had a difficult time in England, when I arrived here," said Boateng, who moved to AC Milan from Portsmouth in 2010.
"I was young, I had all the money, you come here at 20 years (of age) and have to play with Tottenham.
"It was not easy for me. I was choosing the wrong way in that situation because I was not experienced enough.
"Then in Portsmouth I showed what I can do. I showed how I can play football. I think a lot of people appreciated it.
"Now I'm just happy to be back. I love the city of London, I see a couple of friends, and it's always nice to play in England."
The Berlin-born Ghana international likes the anonymity available in London for stars of the Premier League.
"It's so multi-cultured," Boateng said. "You can just enjoy the life here. "Even a good friend of mine, Didier Drogba, if he walks in the street, it's not like people say 'oh my god, there's Drogba'.
"People recognise you, they know who you are, but they leave you in peace.
"It's relaxing to be here, you have good food, good nightlife, like everything is very good here."
Two weeks ago at the Veltins Arena, Boateng was a pale imitation of former Chelsea man Drogba when deployed as a 'false nine', a deep-lying striker.
He hopes to be in his more customary midfield role on Wednesday.
"It's not my favourite position and I haven't played a lot of games in that position," Boateng said.
"Hopefully tomorrow he (coach Jens Keller) is going to put me in another position."
Schalke have won once in England in European competition in six attempts, beating Arsenal in October 2012 at the Emirates Stadium.
Like Boateng, Keller is eager for his side to make an impression in London.
"We haven't won yet against the big boys and we know we've got a really big game ahead of us here," Keller added.
"We're not here just to be visitors. We want to take something from the game."
When Boateng left Milan last summer he was linked with a return to England, but he chose Schalke in part due to their potential.
His three-year spell in Italy was blighted by a racism storm, when he led his Milan team-mates from the field after being the victim of abuse from the crowd during a friendly game in January against fourth division Pro Patria.
Boateng was saddened that the last round of Champions League fixtures was overshadowed by the abuse suffered by Manchester City's Yaya Toure at CSKA Moscow.
"It's impossible that in 2013 things like this still happen," Boateng said.
"I'm very sad for Yaya that he had to experience something like that."