Using your Diskedit or any other hex editor search out the
bytes at the offsets (in hex) 27,28 and 2B,2C these two
pairs should hold the same values.
You should change each pair to the same value.
Let's say, your bytes at 27, 28 are FE 03 then to move a
few steps to the left (and past some irksome door) you will
edit them about 6 less to make F8 03.
If you want to move to the right, you just add 6.