1994 GMC Sonoma Owner's Manual - Page 258

To Remove the Old Wiper Blade: Lift the wiper arm until it locks into a vertical position. 1. Blade Assembly 2. Arm Assembly 3. Locking Tab 4. Blade Pivot 5. Hook Slot 6. Arm Hook 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.