How do I uninstall Second Life I downloaded the Second Life viewer from install.sh
If what you mean is that you downloaded the archive from the Secondlife web site, extracted the archive and ran the install.sh script, it depends on where you installed the client when you run the install.sh script.
If you ran the script without sudo and elected to continue as such accepting all defaults then the client will be installed in your home directory in a folder called .secondlife-install just delete this folder with the following command;
rm -rf ~/.secondlife-install
In System > Preferences > Main Menu, on the left select the Internet group, on the right select the secondlife icon and press the delete button.
If you ran the script as sudo and accepted all defaults then the application will be installed in a folder called secondlife-install under the /opt directory, just remove this directory with the following command;
sudo rm -rf /opt/secondlife-install
As usual just be careful with the commands.
you can remove the .secondlife folder in your home directory if you do not need it for another client or for retaining Secondlife settings if you intend to try the same or another viewer.
It may interest you to note that you do not have to run the install.sh script if you just want to try the viewer and then get rid of it, you can just run the secondlife script in the folder you extracted the archive to. just remember that a .secondlife config and cache directory is created in your home folder this can be deleted safely if you do not have another client that uses that same config and cache directory.