Pick the second bar and change it in one direction (up or down) until first and second bars are equal.
Pick the third bar and change it in one direction until they are equal.

Repeat the process for the next bars until all bars are equal.

Then press DOWN for each bar to increase
OR
Press UP to decrease.

Examples will be added in the future if needed.

P.S. UP = W or Up arrow key, DOWN = S or Down arrow key.