If you have the lowering springs already on the shocks then it is **** easy bud, you already have the hard part done.
Now you can fit these outside on your drive if you want.
FRONT:
*jack up car and secure it in the air (axel stands or bricks)
*remove your front tyres
*look at your old shocker ul have the brake line secured to it just open the clip and pull the line outwards with force
*then undo the 2 bolts at the bottom of the shocker which secure ti to the hub
*open the bonnet and undo the bolt in the engine bay at the top of the strut
*your old shock is now free just pull it out and place your new shcok with lowering spring on
*secure in reverse order
REAR:
*jack up and secure again
*wheels off car
*undo the bottom bolt that is connecting the bottom of the rear shocker to the trailing arm (undo on both sides shockers)
*the trailing arm will now drop down, simply pull out the old springs with your hands
*remove the spring mountings off the old springs and fit to your new ones
*then place the springs back on the axel in correct position then use a jack to lift the whole axel from the middle until the bolt holes in your trailing arms lines up with the bolt holes in your rear shockers
*then simply bolt the bottom of the rear shcoker back to the trailing arms
AND JOB DONE
BTW your nuts will probly be rusty so use some wd40 and work them back and forth on the thread to get them off
simple job mate i did mine myself and i had to take my old springs off the old shcoks and new springs on existing shocks lol
Hope this helps mate
post pics of your car lowered yeah mate