We can solve this together! We're beginning with 51604 and removing 22309 from it.

Step 1: We'll start by subtracting the digit 9 and the borrow 0 from 4 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 0 and the borrow 1 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 3 and the borrow 1 from 6 in column 3 and get 2.
2 is the next digit of our result.

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

So, 51604 - 22309 = 29295.