Upgrading Dell Inspiron n5030 for smooth video editing: is it possible?

Hi there

I regularly edit FullHD video in Adobe Premiere Pro CS5, but its painfully slow and often lags.

I know my Dell Inspiron n5030 is far from a video editing beast, but I'm keen to find out how to upgrade it to make it more video editing friendly.

These are my laptop's specs:

Dual-Core CPU T4500 @ 2.3GHz
Graphics card - Mobile Intel 4 series express chipset family
3GB RAM
Seagate Momentus 5400RPM 320GB Hard Drive

I think it's possible to upgrade RAM to 8GB, and replace the hard drive with a 7200RPM one, but I'm clueless as to whether it's possible to upgrade the Graphics Card and to what? Is it possible to replace my current GC with one that has built-in RAM dedicated to video operation? I can't find this information anywhere.

Any advice would be much appreciated.

Thanks,
Otto