Comprar y instalar Logic Board 661-6491 nos EUA

Donde puedo comprar y instalar la placa lógica en mi Macbook? Puedo aprovechar y poner una placa logica com mas memoria de vídeo?

The MacBook Pro "Core i7" 2.3 15-Inch (Mid-2012/USB 3.0) features a 22 nm "Ivy Bridge" 2.3 GHz Intel "Core i7" processor (3615QM), with four independent processor "cores" on a single silicon chip, a 6 MB shared level 3 cache, 4 GB of 1600 MHz DDR3L SDRAM (PC3-12800) installed in pairs (two 2 GB modules), a 500 GB Serial ATA (5400 RPM) hard drive, an 8X DL "SuperDrive", dual graphics processors -- a NVIDIA GeForce GT 650M with 512 MB of dedicated GDDR5 memory and an "integrated" Intel HD Graphics 4000 graphics processor that shares system memory, as well as an integrated 720p FaceTime HD webcam.