Press the Left Difficulty switch.
There is a large gap in level 2-3 that Louie must cross. Jump on the middle sewer pipe, then jump on the pipe to the left. Walk to the left edge of this pipe and, then run to the right. Continue running until Louie reaches the edge of the third, and lowest, pipe in the series. Then, jump to cross over the sludge gap.
To get three extra cans, get to Level 2 (Eisenhower Lane). You will be standing under a ledge. Go to the end of the ledge, but do NOT go on to the next ledge. If part of your head is still under the ledge, jump up three times to get the extra cans.