Alright, let's solve this problem step by step. We have 63925 and 40604, and we're subtracting the second number from the first.

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

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

Step 3: We'll start by subtracting the digit 6 and the borrow 0 from 9 in column 3 and get 3.
3 is the next digit of our result.

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

Step 5: We'll start by subtracting the digit 4 and the borrow 0 from 6 in column 5 and get 2.
2 is the next digit of our result.

So, 63925 - 40604 = 23321.