- sudo apt-get install texlive-publishers
- Download and save on your Desktop the ACM .cls file from http://www.acm.org/sigs/publications/acm_proc_article-sp.cls
- cd /usr/share/texmf-texlive/tex/latex/acmtrans
- sudo mv ~/Desktop/acm_proc_article-sp.cls acmtrans2e.cls
- sudo cp /usr/share/lyx/layouts/article.layout ~/.lyx/layouts/acmtrans2e.layout
- sudo gedit ~/.lyx/layouts/acmtrans2e.layout
- Change second line # \DeclareLaTeXClass{article} to # \DeclareLaTeXClass[acmtrans2e]{article (ACM)}
- sudo texhash
- In Lyx: Tools --> Reconfigure
- Restart Lyx
- In Lyx: Douments ---> Setting
and right click on the added "BibTex Generated Bibliography" at the end of the lyx document and select settings and "Style" drop down has the "acm".