Well, the part of the contract you have cited says clearly what should be done. It doesn't have to be done by a professional cleaning company, your friend may do it himself, just to leave the apartment in a condition similar to the one it was was when the rent started, of course minus normal wear and tear. However, the dry cleaning and air condition servicing will have to be done by someone who knows how to do it
Our contract was not that detailed, so we have just cleaned the house and did not paint the walls, as this is in our opinion normal wear and tear. However, we have made scratches on a parquet floor, so we had it fixed on our cost. Same with marble floor, we made some serious stains (by stepping on an orange fallen from Chinese New Year tree - acidic thing), so we got it polished by a professional.
Our landlord was quite reasonable one and even thanked us for mopping the floor etc, as she was expecting she will have to do it herself. I know she was an exception, especially reading this board, it seems like most of the landlords are trying to win some extra at the end of the contract.