I wanna know how should i install at least Lion on this laptop but i really want to install Mountain Lion instead...please lemme know what should i get(download) and the steps to install it.

Acer Aspire V3-571g-6407

Intel i5-3210m 2.5Ghz with Turbo Boost up to 3.1Ghz

Nvidia GeForce GT 630M with 1GB dedicated VRam

Intel HD4000(intergrated)

4gb ddr3


OS:Windows 7 Ult.(mbr)(Legacy Bios)but it comes with an efi bios as well because windows 8 was preinstalled but i hate windows 8..loll i LOVE OSX.

Please Help Me Out................... Thank You