It explains it, but how do you execute it? Stumped.
Either from the command line, or launch it from an (executable) script.
Open a terminal cd into the directory that bitcoin-qt is in and type "./bitcoin-qt &" without the quotes the & is there to just free it up from the terminal you opened it up with so you can close it out of the way.
That worked, thank you. Next stumbling block: It seems the data directories for the blocks and wallet have changed? The client starts with 270 weeks back. Where can I set the datadir?