Well first things first you are going to need an External Hard Drive so heres a good one that I bought at Best Buy. http://www.bestbuy.com/site/Seagate/FreeAgentGoFlexDesk1TBExternalUSB2.0HardDriveBlack/9929061.p?id=1218196478313&skuId=9929061
Then I suggest you buy a Western Digital 500gb Internal Hard Drive like this. http://www.bestbuy.com/site/WesternDigital/ScorpioBlue500GBInternalSerialATAHardDriveforLaptops/9172799.p?id=1218044489855&skuId=9172799
Then you have to format your external into FAT32, I have a step by step process here. http://gamrconnect.vgchartz.com/thread.php?id=126296&page=1&str=489824198#
Then once it is in FAT32 hook it up to your PS3 and Back up your old Internal Hard Drive onto your External Hard Drive, you can do that by going to Settings > System Settings > Backup Utility and choose to back up to your External HDD. Then just wait while it backs up.
When its done turn off your PS3 and find yourself a small Phillips-head Screwdriver and unplug all the wires on your PS3, also make sure there aren't any games in it.
Then use this How to video. http://www.youtube.com/watch?v=5sRkj89axOU
Its a long process, sorry.
