Turntable Basics would probably send you a set of instructions if you contact them, and tell them you've lost your instructions, and would like to have them.
The Protractor is not that hard to use. You'll note a hole in the Protractor, and this slips over the Platter Spindle. There is a sight line on the left side of the protractor that runs it entire length, and this sight line must be pointed to the exact center of the Tonearm Pivot to accurately work.
If you're sloppy in this area of alignment, you'll be pretty much wasting your time, as there will be error.
What was suggested to me another good audiogon friend, is to tape a thread at the beginning of the line on the protractor, and use this piece of thread to enchance the aiming accuracy of the sight line to the Tonearm Pivot.
Make sure the thread is exactly on the beginning of the protractor sight line, then pull the thread taught holding the thread to the exact center of the Tonearm Pivot. Now rotate the Protractor on the spindle, while viewing the thread, and the protractor sight line simultaneously, and adjust till the super-impose over one another.
Without moving the protractor, then begin to adjust overhang of the Cartridge until the Stylus itself is exactly within the outer alignment grid's little center box.
Do contantly re-check, with the sight line as you go, making your adjustments to the Cartridge, both as far as overhang go, and Zenith Alignment (the the Cartridge is square-aligned to the lines on the Protractor Grid)
Once you have gotten proper alignment to the Outer Grid, then follow the instructions on the protractor, thus rotating it till you can then set the Stylus on the inner Grid's central reference point. Note how the Cartridge is aligned. if Zenith Alignment is off, slightly compensate back, and forth between the two grids till you get the best possible Zenith Alignment.
This will be your basic Alignment, but do keep in mind that some Cartridge Bodies can be a muther, thus hindering your best attempts (Body isn't square, or a short-low riding Cantilever makes the Stylus hard to see.
As has been told to me, it is the Cantilever, and Stylus itself that must be aligned to the Grid. The Body-Cantilever alignment can be ever so slightly off, even on the best Cartridges.
Do try to use lighting at various angles aimed towards the Stylus (experiment) to help aid what you're seeing, and I've even used a lighted Magnifying Glass so I could better see exactly how well my Cantilever was aligned to the Protractor Grid. Mark