We can solve this together! We're beginning with 666628115 and removing 296200258 from it.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 5 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 5 and the borrow 1 from 1 in column 2 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

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

Step 4: We'll start by subtracting the digit 0 and the borrow 1 from 8 in column 4 and get 7.
7 is the next digit of our result.

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

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

Step 7: We'll start by subtracting the digit 6 and the borrow 0 from 6 in column 7 and get 0.
0 is the next digit of our result.

Step 8: We'll start by subtracting the digit 9 and the borrow 0 from 6 in column 8 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 9: We'll start by subtracting the digit 2 and the borrow 1 from 6 in column 9 and get 3.
3 is the next digit of our result.

So, 666628115 - 296200258 = 370427857.