Dont make it soo hard on your self. Were all volvo owners here, we should be at least one step above the run of the mill GM owner. Extend the trunk fully open. (have somone help) remove the old strut. set the 'C' section of the strut over the connecting rod, C facing down. Use a flat head screw driver and press it in between the top of the 'C' (the bad side of the 'C') and the metal part of the trunk hinge and pull up on the screwdriver ever so lightly. then the 'C' should pop onto the connecting rod. then procede to press on the front ring on to the shaft. Then replace the retaining ring. NOTE!!! One Strut WILL NOT hold up the trunk lid. (my head still hurts)

Any further questions Just ask :)