Recover a brush or brush pack

Hi, I’m not really sure how to use this web more than download brushes and all that, and in advance, I’m sorry for my terrible english.
Well, it happens that I was trying to make a new brush that I needed for a draw, but following a tutorial, the person said that I had to overwrite the brush based on the one I had used, but—without realizing it— the original brush disappeared; I followed every tutorial I could find, and basically ended up deleting(? the krita 4 default resources bundle. Not really sure how, because the archive was there, and suddenly became a folder called modified, and then the bundle didn’t appear at all on krita. Soooo… I’m not really sure what to do because all the tutorials are from four o even six years by far and I could’t find a solution, an actual solution.
I’m going to update krita an see if that solves the problem —which I hope it does— but if not, I would be very grateful if you could help me resolve this. Thanks.