I have knitted the whole of the back of a gillet which has a wide (knit 3, purl 1) hem. The front has pockets which I have knitted as two squares 44 rows deep. As I attached the pockets to the end of the hem, I realise I didn't knit the hem long enough (it's not 44 rows like the pocket so the pocket hangs below the hem!). So, how do I take the hem off the back to reknit it? Can I unravel from the cast-on edge??