Where do I copy this file to?
Paste it into a text editor (Notepad or similar, if you're using WinXP), and name it something identifiable like
Poly Port.sfz. Save it to your Multisamples folder. When you want to try it out (as is), load it into an Element using the Load Multisample dialog.
I see from another thread that you have Rapture. As a single example, let's assume that you're using the GoovePad (mw) preset under Sequences. If you want polyphonic portamento on the first Element, navigate to your
Poly Port.sfz file (through the Multisamples slot), and right-click on it to Open or Edit the file.
Instead of the sample=013 pulse.wav that's in the original online example, change it to sample=089 - fret 01.wav. That's the wavetable that's in the preset itself by default. Save the .sfz file (you can leave the Load Multisample dialog open while you're doing this), and then load it into E1 of the GoovePad preset.
There's a lot of background information and links that'll help at
the Project5 Wiki.
Here's one primer that might get you started.