MacBook – Will this memory fit into the MacBook Pro

1067 Mhz DDR3 is what you care about. You can do it on your own. Apple provides instructions on their website and you can find it on many places too.

For installing the RAM you just need a screwdriver small enough for the screws on the bottom of the computer. After that ground your self or use plastic gloves and take out the old memory put in the new and you are done.

Manufacturers don't matter as long as the memory is 1067 Mhz DDR3 for laptop. Its better to go for well known brands I guess such as kingston,crucial corsair etc.

I bought a Crucial Memory Kit 8GB from amazon for about £35 same type of memory with the one you need and it worked perfect.

While Intel may produce versions of that processor that use an interchangeable socket, all Mac laptops (and almost all other laptops) have their CPUs soldered directly onto the logic board. This means it's effectively impossible to replace them, unless perhaps you have some high-grade industrial soldering knowledge and equipment. You can see this in iFixit's logic board replacement guide for your MacBook Pro.

In addition to that, I'm not aware of anywhere that you can buy individual Intel mobile CPUs. Because they're only used in laptops, they tend to only be sold to OEMs.