Buick 2005 Century Owner's Manual page 286

5. Raise the vehicle by turning the jack handle
clockwise. It should be far enough off the ground
for the spare compact tire to fit underneath the
wheel well.
6. Remove all of the wheel nuts and take off the
flat tire.
5-76
CAUTION:
{
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
the places where the wheel attaches to the
vehicle. In an emergency, you can use a cloth
or a paper towel to do this; but be sure to use
a scraper or wire brush later, if you need to,
to get all the rust or dirt off.
7. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.