OK, let's do this. We've got 72155 and 19633, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 3 and the borrow 0 from 5 in column 1 and get 2.
2 is the first digit of our result.

Step 2: We'll start by subtracting the digit 3 and the borrow 0 from 5 in column 2 and get 2.
2 is the next digit of our result.

Step 3: We'll start by subtracting the digit 6 and the borrow 0 from 1 in column 3 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

Step 4: We'll start by subtracting the digit 9 and the borrow 1 from 2 in column 4 and get -8.
We add -8 to 10 and get 2 as the next digit of the result.

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

So, 72155 - 19633 = 52522.