Alright, ready to do some subtraction? We're taking 68070 and subtracting 18346 from it.

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

Step 2: We'll start by subtracting the digit 4 and the borrow 1 from 7 in column 2 and get 2.
2 is the next digit of our result.

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

Step 4: We'll start by subtracting the digit 8 and the borrow 1 from 8 in column 4 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 5: We'll start by subtracting the digit 1 and the borrow 1 from 6 in column 5 and get 4.
4 is the next digit of our result.

So, 68070 - 18346 = 49724.