How hard is it to replace intake gasket, head gasket and coil pack?

I'm replacing the intake gasket, head gasket and coil pack on a 2002 chevy venture van. It runs good and starts every time but, oil is leaking into coolant and a garage told her that she needs this done.I've done this on other vehicles but, not on anything over 1999. Is there any special tools needed and can it be done from just underneathe the hood? I'm trying to help out an elderly woman down the street with very limited income and she's just buying the parts.
Are all parts acessible from under the hood or do I have remove any thing from inside van to get to it? Thank You!