I have not looked into it on a 986 yet , but I have seen on other h2o Porsches a small tube off one of the top corners of the front radiators. .....
Accessible from the front wheel well , you can unplug it and help bleed air while the rear is jacked .
This will ensure the radiators are vented at initial filling .
Then simply run for a few minutes at 2.5k then top up and cool .
Top up again then do the same again .
There will be points where it bubbles over on idle with the cap removed so it is better to have a helper revving while you top up then replace the cap etc.
If you make the fil-point the high-point of the system it doesn't take long to get the majority of the air out .
Expect to keep your eye on levels and to-up as needed as you drive it over the next couple of weeks though ... Even with a vacuum pull you need to do this