We can solve this together! We're beginning with 4679 and removing 1644 from it.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 9 in column 1 and get 5.
5 is the first digit of our result.

Step 2: We'll start by subtracting the digit 4 and the borrow 0 from 7 in column 2 and get 3.
3 is the next digit of our result.

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

Step 4: We'll start by subtracting the digit 1 and the borrow 0 from 4 in column 4 and get 3.
3 is the next digit of our result.

So, 4679 - 1644 = 3035.