Its difficult but really quite simple, heres how:
In order to fit the shock tower on you must do a little bit of cutting to get it to line up straight. Not only the frame where the new tower sits but all around where the old shock towers were to allow the shocks to sit in place. Then to run screws through the frame it is a task because you cant just drill at the chassis straight on. It requires a careful hand to get the holes drilled in the right place in order to have it straight and give it the strength it has. drilling them too high or low car result in a crack and practically totaled frame but doing them just right will make it indestructible.
Once the shock tower is in place you simply flip the shocks upside down and cut a slit in them just wide enough to snap the shock cap in place of where the original shock went on the control arm. Then just install the pivot balls on the shock tower, snap the shocks on then your done.