I am new to Macs and just downloaded and installed MacTeX along with texmaker. Everything works fine and I am able to successfully create PDFs, but I need to install the "diagrams.sty" package which is not included in the MacTeX packages. I have tried the i-installer, but every time I point it to the address at which the diagrams.sty package is located it tells me that there was an error in downloading (I have tried this for several different mirrors, so I know it's not a problem with the website). I also tried to just put the diagrams.sty file in texmf/tex/latex and then subsequently try to compile a PDF, but that too did not work. Does anyone know how to do this?