Alright, ready to do some subtraction? We're taking 63973 and subtracting 28438 from it.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 3 in column 1 and get -5.
We add -5 to 10 and get 5 as the first digit of the result.

Step 2: We'll start by subtracting the digit 3 and the borrow 1 from 7 in column 2 and get 3.
3 is the next digit of our result.

Step 3: We'll start by subtracting the digit 4 and the borrow 0 from 9 in column 3 and get 5.
5 is the next digit of our result.

Step 4: We'll start by subtracting the digit 8 and the borrow 0 from 3 in column 4 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

Step 5: We'll start by subtracting the digit 2 and the borrow 1 from 6 in column 5 and get 3.
3 is the next digit of our result.

So, 63973 - 28438 = 35535.