GMC 1996 Savana Van Owner's Manual page 264

Replacement blades come in different types and are
removed in different ways.
To
remove the type with a
release clip:
1.
2.
3.
To remove the old wiper blades,
lift the wiper arm
until it locks into a vertical position.
Press down on the blade assembly pivot locking tab.
Pull down on the blade assembly to release
it
from
the wiper arm hook.
Remove the insert .from the blade assembly. The
insert has two notches at one end that are locked by
bottom claws of the blade assembly. At the notched
end, pull the insert from the blade assembly.
4. To install the new wiper insert, slide the notched end
last, into the end with two blade claws. Slide all the
way through the blade claws at the opposite end.
5 . Be sure that the notches are locked by the bottom
claws. Make sure that all other claws are properly
locked on both sides of the insert slots.
6. Put the blade assembly pivot in the wiper arm
hook. Pull up until the pivot locking tab locks in
the hook slot.
7. Carefully lower the wiper arm and blade assembly
into the windshield.
6-40