We can solve this together! We're beginning with 8181 and removing 6020 from it.

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

Step 2: We'll start by subtracting the digit 2 and the borrow 0 from 8 in column 2 and get 6.
6 is the next digit of our result.

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

Step 4: We'll start by subtracting the digit 6 and the borrow 0 from 8 in column 4 and get 2.
2 is the next digit of our result.

So, 8181 - 6020 = 2161.