Minikit 4
Attack the metal spire next to the doorway, then rebuild it into a Resistance flag. There are three additional Resistance flags to raise in the area.
Minikit 5
Choose the left option with the Multi-Build bricks to make a hairdryer that knocks free a boulder and Minikit.
Minikit 6
Melt the ice covering the dive pool near the shielded silver LEGO door. It leads to a second dive pool on the mountainside.