I'm assuming this is for a laptop. As this is an OEM "mobile" processor.
The GPU side of this processor cannot be upgraded because this is an APU processor and the graphics portion is built into the design.
Also, APU's like this are soldered to the motherboard and are not meant to be removed or replaced/upgraded.
Here is some info on it... http://www.cpu-world.com/CPUs/Bulldozer/AMD-A9-Series%20for%20Notebooks%20A9-9420.html
From what I can find the desktop version is using the same processor with the same motherboard socket (FT4).
Acer uses proprietary motherboards (Built to Acer's specification) for each computer so this processor is soldered to the motherboard. So replacing the processor means replacing the motherboard also.
You could check with Acer's customer support to see if they offer upgrades for your system. But, I'm guessing that they would just have you buy a whole new system.