First you need to make sure all the fans are working and are free from dust blocking the vents of fans. If you take off the keyboard you will be able to clean out anything in the case (carefully), and make sure the fans are spinning.
Dude if you need to ask those questions you are not experienced enough to start pulling apart a Laptop. Take it to a Technician. Also consider purchasing a laptop stand that comes with a built in fan for extra cooling.
I don't think you have to take the keyboard off to access the fan. A lot of laptop now have keyboard that are clicked on and have a sheet of metal to seperate the mobo from it so there is little flex and keyboard warming.
Contrary to Wamphryi, I think you should play around with the laptop you have which is not working very well. Everyone need somewhere to start and I think a laptop which is not working so well is a good starting point since you will probably end up buying a new one if overheating persist anyway.
Buy can air. Get screw driver that fit well with the screw (don't use flat on phillips). Work in a well lit hard sturdy surface and don't lose any screw. Have yourself grounded to avoid static charge. Take out the battery and hold the power button for let say 15-30 seconds. Unscrew the biggest bottom cover, which usually covers the mobo with the ram, cpu and gpu and usually you will see it. Smaller cover on the bottom are usually the hdd. But if the biggest cover is not the fan, then yeah open all bottom cover until you find fan. Locate fan and use can air to clean. The put everything back together.
As long as you are grounded, careful not to touch/move any component around and take care of not taking the warranty sticker off, you will be unlikely to damage anything and have your warranty void. Trust me, follow the instruction and be careful, you will be 99.9% ok since I have done it countless time cleaning fan, add ram, swapping hdd, remove original dvd drive and put a secondary hdd bay. Although I have to admitt I have to remove warranty sticker to reapply thermal paste, but nothing goes wrong (temperature is not noticeably different, but my laptop is not overheating to begin with).