Usually, with twin overhead cam engines, you will find the spark plugs in
the center of the cam cover. Because the compression chamber is way down at
the valve level, there is some distance between the plugs and the top of the
cam cover. When you pull the spark plug boots off the plug (by twisting them
circularly until they break free then pulling straight out) you will have an
appreciation of how far down they are. It could easily be several inches.

You will need a spark plug socket and extender to get them out. Some modern
spark plugs are smaller than those in your father's Oldsmobile, so you will
need an appropriate socket. It's a good idea to shoot some air into the hole
before  you take them out to force any crap that may have accumulated there
out. Alternatively, a good vacuum might do. You don't want to drop anything
down into the cylinder. Keep this in mind when the plug is out, since that's
the time gravity will conspire against you.

Another thing to consider is that modern engines tend to have aluminum
heads. That means you should know and observe the torque limit when
installing new plugs. Some folks use the "compress the gasket" rule, but I
like to use a torque wrench. Too loose is also not good;  the heat transfer
from the plug to the head is important. Also, and this is critical:  be
certain to use an anti-seize treatment on the plug threads, else you may not
get them out again. You can buy the stuff at an auto shop.

It's really quite easy, but you need to know the rules.

Best,

Ken