First make sure you have PHP5-CLI and PHP5-GD installed. Then cd to the pts directory (or wherever you saved the files to) and run it from the terminal:
That will give you all the available commands. There are several commands you can append to that initial call, like lists-test and list-suites, which will give you a read-out of all the available benchmarks. You install benchmarks with the install argument. Ex.
Everything will be automatically downloaded and installed, with all dependencies resolved automatically. You're going to need a rather fast internet connection since some of the programs are rather large. After it installs you can run it with the run argument:
Install Universe suite:
./phoronix-test-suite install universe
./phoronix-test-suite run universe