Replace existing 40GB internal HDD in laptop with...

Question

I have a Dell Inspiron 1500 laptop with internal 40GB HDD. Running out of space, I asked Dell for a suitable replacement and was advised the WD1600BEVE 160GB internal HDD from Western Digital. What should I do to transfer all the system and software on existing 40Gb drive to the new 160GB drive? I can do the physical installation of the HDD.