Alright, ready to do some subtraction? We're taking 676407 and subtracting 27820 from it.

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

Step 2: We'll start by subtracting the digit 2 and the borrow 0 from 0 in column 2 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 3: We'll start by subtracting the digit 8 and the borrow 1 from 4 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 7 and the borrow 1 from 6 in column 4 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 5: We'll start by subtracting the digit 2 and the borrow 1 from 7 in column 5 and get 4.
4 is the next digit of our result.

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

So, 676407 - 27820 = 648587.