replacing front ignition coil on V6 cracked by oil in chamber?

[blueysaloon]

Both front and back coils only recently replaced, but oil went into a chamber when topping up engine, and this coil is now cracked badly. I will not spill any again, but does anyone have any tips, does coil have to be sealed. I could see a small amount of sealant on base of previous coil, but had this been done properly should this have been relied on to not allow oil to enter chamber? Where is easiest place to get Haynes manual for a V6 1996 saloon.

Thanks