We can solve this together! We're beginning with 990306992 and removing 545097003 from it.

Step 1: We'll start by subtracting the digit 3 and the borrow 0 from 2 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 9 in column 2 and get 8.
8 is the next digit of our result.

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

Step 4: We'll start by subtracting the digit 7 and the borrow 0 from 6 in column 4 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 5: We'll start by subtracting the digit 9 and the borrow 1 from 0 in column 5 and get -10.
We add -10 to 10 and get 0 as the next digit of the result.

Step 6: We'll start by subtracting the digit 0 and the borrow 1 from 3 in column 6 and get 2.
2 is the next digit of our result.

Step 7: We'll start by subtracting the digit 5 and the borrow 0 from 0 in column 7 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

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

Step 9: We'll start by subtracting the digit 5 and the borrow 0 from 9 in column 9 and get 4.
4 is the next digit of our result.

So, 990306992 - 545097003 = 445209989.