How to add a bit with nibble

First, create a number with N-th bit set and all other bits clear. This value is 1 << N.
On next step, take your original value and calculate the bitwise OR with the value from the previous step.
That is:

int N = //... bit number
int value = //... can be any integer type, signed or unsigned
value |= 1 << N; // same as:
value = value | (1 << N)

To clear a bit, use bitwise AND with the complement:

value &= ~(1 << N);

That's all. Learn the bitwise operators: http://www.learncpp.com/cpp-tutorial/38-bitwise-operators[^].

—SA