Upgrade Mac Mini intel processor & graphics processor?

I just purchased a mid 2011 Mac Mini i5 2.3ghz 8gb RAM and Intel HD Graphics 3000. My question is, is it possible to manually upgrade the processor to the i7 quad-core 2.0ghz or 2.7ghz processor's or the i5 dual-core 2.5ghz processor? According to the spec sheet, they are all accompanied by the Sandy Bridge so it seems that interchanging should be possible, however, when customizing on Apple.com the 2.3ghz model does not offer an upgrade option for the processor.

Also, would it be possible to upgrade the graphics processor from the Intel HD 3000 to the AMD Radeon HD 6630M?

Can any offer some insight here? Thanks