Probably not possible. Laptops usually use the dedicated graphics in the CPU (i.e. Intel HD series); since they share memory with the OS, the only way to increase that is to increase the laptop's total RAM...and even then, it still may have a hardcoded upper limit for the video portion.
For the ones that have a discrete "mobility" card inside, "upgrading" the memory works just like with a desktop: you have to replace the entire card. Unfortunately, replacing a graphics card in a laptop is extremely difficult, due to the limited space, problems with disconnecting then reconnecting all of the pieces (keyboard, mouse pad, etc.), & the problem that all too often components like that are soldered or glued into place to preven removal by...