We can solve this together! We're beginning with 4260 and removing 2156 from it.

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

Step 2: We'll start by subtracting the digit 5 and the borrow 1 from 6 in column 2 and get 0.
0 is the next digit of our result.

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

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

So, 4260 - 2156 = 2104.