removing the top plastic cover
Do you mean the one that covers the Battery? It has release tabs at the bottom of the cover ,,, you push them in and the cover releases
This may help. http://www.cargurus.com/Cars/Discussion-t35456_ds539778
This is to remove the spark plug but it shows removing the cover. http://www.paulstravelpictures.com/2008-2012-GM-Chevrolet-Malibu-Ecotec-LE5-I4-Engine-Spark-Plugs-Replacement-Guide/
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