After you downloaded your necessary macros / plugins from CTAN, you can extract them to your local „tex repository“. This is located in you home folder (if it is not there, just create that structure):
/home/myUser/texmf/tex/latex/
Inside that directory you can create a directory with the name of the zip file. Here is an example for the macro „moderncv.zip“
/home/myUser/texmf/tex/latex/moderncv/
Extract the zip file in that directory. In my example this results in:
/home/myUser/texmf/tex/latex/ |-- moderncv | |-- moderncv | | |-- CHANGELOG | | |-- examples | | | |-- picture.eps | | | |-- picture.jpg | | | |-- publications.bib | | | |-- template_banking_black.pdf | | | |-- template_banking_red.pdf | | | |-- template_casual_orange.pdf | | | |-- template_classic_green.pdf | | | |-- template-es.pdf | | | |-- template-es.tex | | | |-- template_multibib.pdf | | | |-- template_oldstyle_grey.pdf | | | |-- template.pdf | | | |-- template.tex | | | |-- template-zh.pdf | | | `-- template-zh.tex | | |-- KNOWN_BUGS | | |-- moderncv.cls | | |-- moderncvcolorblack.sty | | |-- moderncvcolorblue.sty | | |-- moderncvcolorgreen.sty | | |-- moderncvcolorgrey.sty | | |-- moderncvcolororange.sty | | |-- moderncvcolorpurple.sty | | |-- moderncvcolorred.sty | | |-- moderncvcompatibility.sty | | |-- moderncvstylebanking.sty | | |-- moderncvstylecasual.sty | | |-- moderncvstyleclassic.sty | | |-- moderncvstyleempty.sty | | |-- moderncvstyleoldstyle.sty | | |-- README | | `-- tweaklist.sty | `-- moderncv.zip
After you extracted the zip file, you have to register those files for tex (with root):
sudo texhash
After that your macros should be available for the tex compiler.