Slide the blue part back as far as you can, the cable then sits in a slot and the blue bit slides back over the cable locking it in place. You might have to wriggle the assembly around a bit to get it to snap back into place securely. The blue bit should cover the cable.
img]http://986forum.com/forums/uploads01/Pic051327339791.jpg[/img]
here is a link to an excellent walk thru at Pelican parts
Pelican Technical Article: Installing a Boxster Short Shift Kit (SSK) and Replacing Boxster Shift Bushings - 986 / 987
I did mine a couple of weeks ago and thats how it worked. its been fine since!
hope this helps