Really this speaks for itself - the first step to re-making this crocheted top is to take it apart!
I've opened the side seams as currently the garment is FAR too small for me and opened the front as I intend to turn it into a waistcoat.
Next step will be to make the neck wider and remove most of the sleeve sections. Then comes the difficult part - finding more yarn for extra patches and working out where to add the new ones, particularly if they aren't the same colours.