Increased the dedicated video RAM in Dell A10-8700P R6

I have bought a new Dell Inspiron 15 5000 Series (AMD). Everything works fine except one thing.

There is a problem with my dedicated video memory. I have 12go of memory. and the dedicated video memory is only 512MB. I need more dedicated memory. How increase the dedicated video memory?

I shall be very thankful to you if you helped me resolve this issue.