We can solve this together! We're beginning with 840063 and removing 77038 from it.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 3 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 3 and the borrow 1 from 6 in column 2 and get 2.
2 is the next digit of our result.

Step 3: We'll start by subtracting the digit 0 and the borrow 0 from 0 in column 3 and get 0.
0 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 7 and the borrow 1 from 4 in column 5 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

Step 6: We'll start by subtracting the digit 0 and the borrow 1 from 8 in column 6 and get 7.
7 is the next digit of our result.

So, 840063 - 77038 = 763025.