We can solve this together! We're beginning with 40455 and removing 39342 from it.

Step 1: We'll start by subtracting the digit 2 and the borrow 0 from 5 in column 1 and get 3.
3 is the first digit of our result.

Step 2: We'll start by subtracting the digit 4 and the borrow 0 from 5 in column 2 and get 1.
1 is the next digit of our result.

Step 3: We'll start by subtracting the digit 3 and the borrow 0 from 4 in column 3 and get 1.
1 is the next digit of our result.

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

Step 5: We'll start by subtracting the digit 3 and the borrow 1 from 4 in column 5 and get 0.
0 is the next digit of our result.

So, 40455 - 39342 = 1113.