Possible the strut is actually gone.
Taking strut out:
Outside - Jack car up, remove wheel. Remove endlink(if applicable). Remove 2x17mm bolts that run parallel to the ground.
Inside - Remove rear deck lid cover. Remover seat belt spool remove three 14mm nuts from the top of the strut. It is nice to have someone outside holding the strut to keep it from falling down. Or you could do the the inside steps first.
Removing Mount:
You need a spring compressor(unless you have lowering springs like the pro-kit which there is no tension on the spring when it is assembled and you can just take the nut off and not risk it bashing you in the face), 17mm socket, impact gun is preferred and the remove top nut, take "wing" washer off, then remove mount replace with new one. Just take note of the order of any washers or the pieces you take off and install in reverse order.
I will be replacing my rear struts AGAIN! as soon as a member on here gets back to me on the shipping of two struts. So if it comes down to it I can take pics, but I believe there is a thread on how to do struts on our cars.