http://carlo-hamalainen.net/blog/?p=8
But I found I needed a little fiddling. Here's what I did:
cd ~/Desktop
texmf_folder=~/Library/texmf/
curl http://mirror.ctan.org/fonts/mnsymbol.zip > mnsymbol.zip
unzip mnsymbol.zip
cd mnsymbol/tex
latex MnSymbol.ins
mkdir -p $texmf_folder/tex/latex/MnSymbol/
mkdir -p $texmf_folder/fonts/source/public/MnSymbol/
mkdir -p $texmf_folder/doc/latex/MnSymbol/
cp MnSymbol.sty $texmf_folder/tex/latex/MnSymbol/MnSymbol.sty
cd ..
cp source/* $texmf_folder/fonts/source/public/MnSymbol/
cp MnSymbol.pdf README $texmf_folder/doc/latex/MnSymbol/
mkdir -p $texmf_folder/fonts/map/dvips/MnSymbol
mkdir -p $texmf_folder/fonts/enc/dvips/MnSymbol
mkdir -p $texmf_folder/fonts/type1/public/MnSymbol
mkdir -p $texmf_folder/fonts/tfm/public/MnSymbol
cp enc/MnSymbol.map $texmf_folder/fonts/map/dvips/MnSymbol/
cp enc/*.enc $texmf_folder/fonts/enc/dvips/MnSymbol/
cp pfb/*.pfb $texmf_folder/fonts/type1/public/MnSymbol/
cp tfm/* $texmf_folder/fonts/tfm/public/MnSymbol/
sudo mktexlsr
sudo updmap-sys --enable MixedMap MnSymbol.map
curl http://mirror.ctan.org/fonts/minionpro/scripts.zip > scripts.zip
mkdir minionpro-scripts
cd minionpro-scripts
unzip ../scripts.zip
find /Library/Fonts/ -iname '*minion*pro*otf' -exec cp -v '{}' otf/ ';'
sudo apt-get install lcdf-typetools
./convert.sh
mkdir -p $texmf_folder/fonts/type1/adobe/MinionPro/
cp pfb/*.pfb $texmf_folder/fonts/type1/adobe/MinionPro/
# It turned out to be very important to get this 2.030 version; a mismatch gives missing characters!
curl https://lists.berlios.de/pipermail/minionpro-devel/attachments/20090814/4e956ea2/attachment.zip > enc-2.030-beta.zip
curl http://mirror.ctan.org/fonts/minionpro/metrics-full.zip > metrics-full.zip
curl http://mirror.ctan.org/fonts/minionpro/metrics-base.zip > metrics-base.zip
curl http://mirror.ctan.org/fonts/minionpro/metrics-opticals.zip > metrics-opticals.zip
cd $texmf_folder
unzip ~/Desktop/metrics-base.zip
unzip ~/Desktop/metrics-full.zip
unzip ~/Desktop/enc-2.030-beta.zip
sudo mktexlsr
sudo updmap-sys --enable MixedMap MnSymbol.map
