Align the two binary numbers by place value
Start subtracting from the rightmost bit
If the top bit is greater than or equal to the bottom bit, subtract directly
If the top bit is smaller than the bottom bit, borrow 1 from the next left bit
When borrowing, turn the current bit into 2 in binary form
Continue subtracting each pair of bits from right to left
If needed, keep borrowing through consecutive zeros
Write the result bit for each position
Remove any leading zeros in the final answer