OK, let's do this. We've got 86196 and 81378, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 6 in column 1 and get -2.
We add -2 to 10 and get 8 as the first digit of the result.

Step 2: We'll start by subtracting the digit 7 and the borrow 1 from 9 in column 2 and get 1.
1 is the next digit of our result.

Step 3: We'll start by subtracting the digit 3 and the borrow 0 from 1 in column 3 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 4: We'll start by subtracting the digit 1 and the borrow 1 from 6 in column 4 and get 4.
4 is the next digit of our result.

Step 5: We'll start by subtracting the digit 8 and the borrow 0 from 8 in column 5 and get 0.
0 is the next digit of our result.

So, 86196 - 81378 = 4818.