First I think if your laptop does not have a single screw to replace harddisk design. I believe you should head down to ur local Sears tools department and get a size 8 or 9 torx screw driver. Do not get size10 it will not fit and you will end up striping ur screw.
The design I am familiar with is two screw to remove panel above keyboard(location of leds and or power buttons ect. Some design have two or more
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For this type of catch design you gotta risk a little b pressing on the edges with a flat head screwdriver and then pry.
Anyway, hopefully you dont have to do this.
The front part(palm/ mouse pad portion of the laptop should be detacheble, similar bottom screws and catch on the sides. Just apply slight pressure to the area when there is a "catch" hook or whatever you call it and then pry.
Be gentle.