I can change the cpu?

Sorry the chip its self is not socketed as such you can’t replace it.

But! What you can do is swap out the logic board with a better CPU. This series also has a known issue with the dedicated GPU I would recommend you look at installing a 2012 logic board to get both a better CPU but also a better GPU!

The board is a direct drop in with just one minor alteration needed in the LVDS cable as the newer board has a slightly different connector. All you need to do is use a nail file to file down the cable connectors tang ever so slightly on both sides.

Here’s the logic board info for the 2012 boards

• 661-6491 - 15” Macbook Pro 2.3GHz i7
• 661-6492 - 15” Macbook Pro 2.6GHz i7
• 661-6493 - 15” Macbook Pro 2.7GHz i7

Here’s one source for the part 15” Macbook Pro 2.6GHz i7 Logic board

And here’s the guide to put it in MacBook Pro 15" Unibody Early 2011 Logic Board Replacement