Installing fonts on a GNU/Linux machine is really simple; you just have to move them to a /usr/share/fonts/ folder and update the font cache. Thanks to Linux And Friends for providing me with this solution. Alright, let's begin.
Download the font packages
wget http://sourceforge.net/projects/sourcecodepro.adobe/files/SourceCodePro_FontsOnly-1.017.zip && wget http://sourceforge.net/projects/sourcesans.adobe/files/SourceSansPro_FontsOnly-1.038.zipExtract the files
unzip SourceCodePro_FontsOnly-1.017.zip && unzip SourceSansPro_FontsOnly-1.038.zipCopy the files to appropriate folders
sudo mv SourceCodePro_FontsOnly-1.017/OTF/ /usr/share/fonts/opentype/SourceCodePro/ && sudo mv SourceCodePro_FontsOnly-1.017/TTF/ /usr/share/fonts/truetype/SourceCodePro/Force (-f) a rebuild of the font information cache and show what's happening (-v)
sudo mv SourceSansPro_FontsOnly-1.038/OTF/ /usr/share/fonts/opentype/SourceSansPro/ && sudo mv SourceSansPro_FontsOnly-1.038/TTF/ /usr/share/fonts/truetype/SourceSansPro/
sudo fc-cache -fvAnd that's all! The fonts are now installed for all users on your system.