I had planned to write this up once, but many folks have beat me to it - and thanks to google, I found several examples on line. The info at
Pelican Parts is the one that is almost identical to the process I use, right down to the same filter wrench I found to fit the Boxster filter housing.
A prior thread on this site
here as well.
My last filter was under $15 at the dealership (mention PCA membership and most will give you 10% off).