Alright, let's solve this problem step by step. We have 77621 and 52255, and we're subtracting the second number from the first.

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

Step 2: We'll start by subtracting the digit 5 and the borrow 1 from 2 in column 2 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

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

Step 4: We'll start by subtracting the digit 2 and the borrow 0 from 7 in column 4 and get 5.
5 is the next digit of our result.

Step 5: We'll start by subtracting the digit 5 and the borrow 0 from 7 in column 5 and get 2.
2 is the next digit of our result.

So, 77621 - 52255 = 25366.