How do I replace the video card in a Sony PCG-GRT270 Laptop ?

I am using a dell laptop so i hope replacing video card in your laptop uses the same steps(checkout):-

• Remove the battery from the laptop.
• Unplug the AC adapter.
  
• Lay the LCD screen flat down.
  
• Remove the front bezel on your laptop using a flat-head screwdriver to gently pry it loose.
  
• Unscrew the keyboard screws.
  
• Carefully push the keyboard forward, then lift it off the laptop. It is not necessary to remove the keyboard completely.
  
• Remove the LCD ribbon connector by gently pulling on the tag.
  
• Remove the four screws that hold the video card in place.
  
• Lift the video card out of the laptop.
  
• Place the new video card in place.
  
• Replace the four screws.
  
• Re-attach the ribbon connector for the LCD.
  
• Replace the keyboard and screw back into place.
  
• Replace the front bezel on the laptop.
  
• Replace the battery and power up the computer.
  

You cannot replace the video card on a laptop, they are built-in on the motherboard.