Name                    Last modified       Size  Description

 Parent Directory        10-Mar-2019 06:43      -  
 2up-doc.pdf             15-May-2010 17:27    62k  
 2up-doc.tex             15-May-2010 17:29    17k  
 2up.sty                 15-May-2010 17:29     1k  
 2up.tex                 15-May-2010 17:29    12k  
 Changes                 15-May-2010 17:29     1k  
 Makefile                15-May-2010 17:10     2k  

Save the files 2up.sty|tex in a directory, which is part of your 
local TeX tree. 
Then do not forget to run texhash to update this tree.
For more information  see the documentation of your LATEX distribution 
on installing packages into your LATEX distribution or the 
TeX Frequently Asked Questions:
(http://www.tex.ac.uk/cgi-bin/texfaq2html?label=instpackages).