I've never been able to get the gear knob off mine either, but
apparently it just pulls off.
You need to get the ALShift.exe util off their webbie or the CD that
came with the shifter and leave it running in the background when you
start gpl. You will then be able to use either the paddles on your wheel
as usual or the shifter to direct-select.
You can also patch gpl with gplshift, but I haven't done this because I
prefer to be able to use either shifting method, gplshift will disable
your paddles by default.
Some titles support the shifter natively (NR2003, LFS etc) so with those
you don't need to use ALShift.
Malc.
I changed the knob with the one from my car so it's easier to remove now to
change plate.
Using the Act-Labs Shifter Utility v2.2 from Act-Labs, GPL should work
automatically.
I've had mine for more than 3 years and I don't remember having to do
anything special for it to work.