Alright, let's solve this problem step by step. We have 20308 and 17178, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 8 in column 1 and get 0.
0 is the first digit of our result.

Step 2: We'll start by subtracting the digit 7 and the borrow 0 from 0 in column 2 and get -7.
We add -7 to 10 and get 3 as the next digit of the result.

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

Step 4: We'll start by subtracting the digit 7 and the borrow 0 from 0 in column 4 and get -7.
We add -7 to 10 and get 3 as the next digit of the result.

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

So, 20308 - 17178 = 3130.