We can solve this together! We're beginning with 81887 and removing 8502 from it.

Step 1: We'll start by subtracting the digit 2 and the borrow 0 from 7 in column 1 and get 5.
5 is the first digit of our result.

Step 2: We'll start by subtracting the digit 0 and the borrow 0 from 8 in column 2 and get 8.
8 is the next digit of our result.

Step 3: We'll start by subtracting the digit 5 and the borrow 0 from 8 in column 3 and get 3.
3 is the next digit of our result.

Step 4: We'll start by subtracting the digit 8 and the borrow 0 from 1 in column 4 and get -7.
We add -7 to 10 and get 3 as the next digit of the result.

Step 5: We'll start by subtracting the digit 0 and the borrow 1 from 8 in column 5 and get 7.
7 is the next digit of our result.

So, 81887 - 8502 = 73385.