Help adding brushes to mac

Hi I am new to Krita and not a tech person. I bought brushes to add, follow youtubes and tutorials, it does not work. When I downloaded the bought file, there is 2 things in the folder: one is a pdf file showing drawings made with every single brush, the second is a .bundle . There is no zip to unzip. When I click on the .bundle my mac says I have nothing to open this, and I can either use aomething I have to open it or look on apple to find something. I do understand how to add brushes within krita. When I try to import a .bundle file, of course it says failed. I am sure it is very simple and obvious to all. But not for me. Maybe its a mac thing and those brushes pack will never work there. Krita works perfectly fine on my mac. I just want more realistic brushes that looks like real oil painting.