1: Complete the dance off in the construction yard while getting 3 “awesome” hits.
Escape from BricksBurg
2: Have Benny to use the terminal in the upper left room to open the main door in the Control Room. Once done, run across the bridge to grab them.
3: When you reach solid ground, in free-play mode, have someone with a laser go to the fence on the far right and break the gold lock. Go to the roof of the barn and drill the wall to open the doors below revealing the pants.
4: After the first checkpoint, you will need to use barrels to destroy the three rooftop ladders. After the master build, cross the bridge and then jump down, over the edge with Unikitty to the platform below where there is a rainbow door. Smash and go through to enter a saloon. Stand at the large window in the rear and you will need to shoot 10 enemies in a shooting gallery style shootout. Once completed, the pants will be in the center of the room.
Escape from Flatbush
5: At the very start of the level, use a flying character to go to the left. Break the gold hatch and then drop into the train car. Once in, blast the gold bars on the right and put them together. Then burn off the safe door and build again. Now set the color switches on the left and right as they are in the image and the pants will appear when the center chest opens.