if you take the top bit off (between the screen bottom and the keyboard) - should clip off - then take out the keyboard... then.. maybe you can clip off the rest of the top to remove it.. (at a guess) the acer laptops I have had have all been made so as to NOT be taken apart - unlike my old dell P2 lappy that could be totally dismantled in mins
I would search around online for a disassembly guide - http://repair4laptop.org/disassembly_acer.html has some Aspire 3000 guides, but I don't know if they are the same series as yours. Check them out though