$> sudo chmod +x <<relative path to your LPL download>> eg. ~/Desktop/LPL-2_7&tc-deb-installer
enter password, and wait a fraction of a second # this makes the file executable. It wasn't. That's why every lazy way you tried to get it working failed.
$> sudo (eg) ~/Desktop/LPL-2_7&tc-deb-installer #execute the shell script by telling the shell its name
That's it! Now you can start to fight to get the thing to work. Have lots of fun, as SuSE used to say.
If just using the path and filename doesn't work, try appending the command sh. (ie, specify in "black and white" that what you want to do here is run a shell script).