The cpu socket is normally covered by a fan that needs to be unscrewed. Incase im wrong because i have only changed computer cpu's not laptop checkout this: http://www.insidemylaptop.com/take-apart-dell-inspiron-1720-1721-dell-vostro-1700-laptop/ Dont forget to touch a metal surface not connected to the laptop frequently as you can destroy your motherboard with static electricity.
Aspire 5335 Series Specifications link http://support.acer.com/acerpanam/notebook/0000/Acer/Aspire5335/Aspire5335sp2.shtml http://www.intel.com/products/processor/celeron/mobile/specifications.htm IntelĀ® Processor Identification Utility link http://www.intel.com/support/processors/tools/piu/sb/CS-014921.htm
Try this out http://www.cpuid.com/cpuz.php CPU-Z is probably my favorite for looking at a computer's internals without opening it up.