Let's get this math done. We have 91004 and 58512, and we're going to subtract the second number from the first.

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

Step 2: We'll start by subtracting the digit 1 and the borrow 0 from 0 in column 2 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 3: We'll start by subtracting the digit 5 and the borrow 1 from 0 in column 3 and get -6.
We add -6 to 10 and get 4 as the next digit of the result.

Step 4: We'll start by subtracting the digit 8 and the borrow 1 from 1 in column 4 and get -8.
We add -8 to 10 and get 2 as the next digit of the result.

Step 5: We'll start by subtracting the digit 5 and the borrow 1 from 9 in column 5 and get 3.
3 is the next digit of our result.

So, 91004 - 58512 = 32492.