The plastic cover over the battery is held on by the battery cables. Remove the cables, remove the cover, and you will have access to the hold down.
For the 2007-2011 Camry Hybrid, that battery costs $4,892. Four thousand, eight hundred, and ninety two dollars. How many miles would you have to drive in a hybrid to save that much money? The price of the battery can be reduced by $1,350 with a “core credit” through a long-established Toyota program.