No problem, let's work through this together. We're starting with 629986 and are subtracting 68131 from it.

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

Step 2: We'll start by subtracting the digit 3 and the borrow 0 from 8 in column 2 and get 5.
5 is the next digit of our result.

Step 3: We'll start by subtracting the digit 1 and the borrow 0 from 9 in column 3 and get 8.
8 is the next digit of our result.

Step 4: We'll start by subtracting the digit 8 and the borrow 0 from 9 in column 4 and get 1.
1 is the next digit of our result.

Step 5: We'll start by subtracting the digit 6 and the borrow 0 from 2 in column 5 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

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

So, 629986 - 68131 = 561855.