Alright, ready to do some subtraction? We're taking 62813 and subtracting 42004 from it.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 3 in column 1 and get -1.
We add -1 to 10 and get 9 as the first digit of the result.

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

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

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

Step 5: We'll start by subtracting the digit 4 and the borrow 0 from 6 in column 5 and get 2.
2 is the next digit of our result.

So, 62813 - 42004 = 20809.