In addition to the trunk release button on the Remote Keyless Entry (RKE) transmitter, the trunk can be opened from inside the vehicle by pressing the remote trunk release button. This button is located inside the driver storage compartment, on the left side of the instrument panel.
See Trunk.
Door Locks
WindowsChevrolet Cobalt Service & Repair Manual. Engine Oil Pan Gasket R&R
1.
Install the engine support fixture.
2.
Remove the engine mount.
3.
Raise the engine enough to allow clearance
for the oil pan removal.
4.
Raise and support the vehicle.
...