Alright, ready to do some subtraction? We're taking 496020 and subtracting 20913 from it.

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

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

Step 3: We'll start by subtracting the digit 9 and the borrow 0 from 0 in column 3 and get -9.
We add -9 to 10 and get 1 as the next digit of the result.

Step 4: We'll start by subtracting the digit 0 and the borrow 1 from 6 in column 4 and get 5.
5 is the next digit of our result.

Step 5: We'll start by subtracting the digit 2 and the borrow 0 from 9 in column 5 and get 7.
7 is the next digit of our result.

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

So, 496020 - 20913 = 475107.