Just bought a 2008 MBAluminum from a friend. I am wondering if I can add RAM to it from a couple of sources: Can I add RAM from this laptop to it? asus u46e-bal5 Can I add RAM from a 2013 MB air to it? Also: My trackpad won't click - I think it is a battery issue. How do I replace the battery? Where would I get one? Thanks. ---------- Also, will Yosemite work on it? Even if I do install more RAM?