When you say "project" do you man the Premiere Elements .prel file? Or do you mean the video you've output from it?
The easiest way to move the .prel file is to go to the program's File menu and select Save As, then save it to your new location.
However that only moves the project file. Any media files you have linked to it will remain where they are.
I guess the exact instructions depend on what exactly you're trying to move. And how your drives are connected to your system.
Well actually I am trying to move everything, the .pre file and all the video files and everything else associated with the project. I guess there must be a way?
Under the File menu is the Project Archiver. This will copy your project file and all its attached media to any new location. You can then delete the files from your old drive.
Great - I have tried it and it works a treat, I find it odd it changes the file names, but hey that's trivia I guess.