GMC 2001 C3 Owner's Manual page 294

1. To remove the engine air cleaner/filter, loosen the
screws on the cover of the housing.
2. Lift the cover upward and remove the air
cleaner/filter from the housing. Care should be taken
to dislodge as little dirt as possible.
3. Clean the filter sealing surface and the housing.
4. Install the new engine air cleaner/filter.
5. Reinstall the cover and tighten the screws.
6-18
Refer to the Maintenance Schedule to determine when to
replace the engine air cleaner/filter. See "Owner Checks
and Services" in the Index.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can easily
get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.