you can only upgrade laptop GPU's on high end rigs from 2008-2012 that support more than 1 model of GPU on MXM slot.
Integrated GPU is now in the processor and dedicated GPU is soldered.
There is no way to upgrade laptop GPU's on consumer grade laptops.
The MXM interface is generally reserved for higher end GPUs. Like the GTX 560m back when it was new. Additionally that format is generally used in specific gaming laptop models that costs at least $1,400. The key phrase is "specific" so you must do research.