How do I restore my VRAM

Could you be a bit more clear as to what you are asking? Video RAM (or VRAM) is generally managed by the OS. However, the MacBook does not have any dedicated VRAM. The graphics subsystem shares memory with the system RAM. What exactly are you trying to do or what is happening that you feel there is a problem?

VRAM is shared with your regular RAM.
It will raise and lower as necessary.

OliveMollieTree wrote:
I want to get the Sims 3 but it says I need 128 MB of VRAM and I have 144 MB on my computer and i dont know if it will affect my computer

It shouldn't have any negative effects on your system. The OS is designed to use a minimum of 144 MB for VRAM and dynamically adjusts. If you have at least 2 GB total memory, it's little to worry about. There really isn't anything you can do to change how much memory your system allocates to different resources.