No problem, let's work through this together. We're starting with 339902 and are subtracting 35764 from it.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 2 in column 1 and get -2.
We add -2 to 10 and get 8 as the first digit of the result.

Step 2: We'll start by subtracting the digit 6 and the borrow 1 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 7 and the borrow 1 from 9 in column 3 and get 1.
1 is the next digit of our result.

Step 4: We'll start by subtracting the digit 5 and the borrow 0 from 9 in column 4 and get 4.
4 is the next digit of our result.

Step 5: We'll start by subtracting the digit 3 and the borrow 0 from 3 in column 5 and get 0.
0 is the next digit of our result.

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

So, 339902 - 35764 = 304138.