I have followed the tutorial for removing SecuROM over at MATY, but found some of it to be a bit confusing.
I found this link today, followed the steps and I am now SecuROM FREE...
Please note that to REMAIN free from SecuROM, you can no longer run your game from the CD or DVD that you purchased and that you must download a "No CD (or DVD) Patch". This is an executable file that will start your Sims 2 game when you click on the icon. You must get the patch for the EP that you last installed, so you will have to search for the appropriate file.
Hopefully this will help you as much as it did me!