* Unpick the hood where it crosses over itself in front, leaving about a 2" gap
* Turn the hoodie inside out and find the center of the front (from the neck to the bottom), then mark a line down the center
* Iron a 5/8" wide piece of fusable, lightweight interfacing from the neck to the bottom of the hoodie, along the line you drew
* Pin a separating zipper (with the zipper head on the inside) on top of the 5/8" interfacing you just ironed on the center line. Baste with big stitches down both sides.
* Use your sewing machine with a zipper foot to sew down both sides of the zipper, about 1/4" from the zipper itself.
* Turn hoodie right side out and very carefully slide your scissors between the zipper and the hoodie so you're only cutting the hoodie - not the zipper. Then cut all the way up between the two lines of stitching, unzip the zipper, and there you go!