Removing a specific Pen Tool on top of another

[d.carousel]

I'm remembering lots of things I used to do. 

With the white areas, how can I make them turn into the background?

[sishamIAGD]

This all depends on how you got to this point? How are you creating it?

[c.pfaffenbichler · Accepted solution]

One can use Pathfinder or Object > Compound Path > Make to punch out a shape from another one. 

[d.carousel]

The Pathfinder works well. Thanks.