OK, let's do this. We've got 995219 and 77995, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 5 and the borrow 0 from 9 in column 1 and get 4.
4 is the first digit of our result.

Step 2: We'll start by subtracting the digit 9 and the borrow 0 from 1 in column 2 and get -8.
We add -8 to 10 and get 2 as the next digit of the result.

Step 3: We'll start by subtracting the digit 9 and the borrow 1 from 2 in column 3 and get -8.
We add -8 to 10 and get 2 as the next digit of the result.

Step 4: We'll start by subtracting the digit 7 and the borrow 1 from 5 in column 4 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 5: We'll start by subtracting the digit 7 and the borrow 1 from 9 in column 5 and get 1.
1 is the next digit of our result.

Step 6: We'll start by subtracting the digit 0 and the borrow 0 from 9 in column 6 and get 9.
9 is the next digit of our result.

So, 995219 - 77995 = 917224.