After the plastic cover is removed ( six torx screws) : on the right is a
small coil and some capacitors. On the left is a black module. I suspect
that this is the control module that switches the spark to each of the 4
output coils. As you can see, the four individual ignition coils are easy to
change.  The primary resistance of each coil  was less than 1 ohm and the
seconday resistance ranged between 830 and 840 ohms. It is also easy to see
that they are partly oil filled. Given the cost of these cassetes, this
could be useful information to fellow DYIers.
View photos at
 http://ca.pg.photos.yahoo.com/ph/radiodognot/album?.dir=/b31c

Hopefully the link works!!