The answer is 6
Step one: Simplify the expressions inside the absolute value bars
|-6|-|6|-(-6)=|-6|-|6|-(-6)
|-6|-|6|-(-6)=|-6|-|6|-(-6)
Step two: take the absolute value of the resulting number
|-6|-|6|-(-6)=6-|6|-(-6)
6-|6|-(-6)=6-6-(-6)
Step three: simplify the numeric expression
6-6-(-6)=6