Yep - I did a write up about this some 6-9 months ago !
I'll see if I can find it !
EDIT - here it is :-
This is for version 908 :-
Ignition on - engine off
Select Engine controller 01
Select Measuring blocks 08
Select 'Go' in Group 1
Start Engine ( you may be able to start engine earlier but I don't )
Hit 'Turbo' button at top of page
Select Adaptation - 10
Change channel to 06 and hit 'Read'
First figure shows actual rpm
Stored value shows rpm as originally set ( mine is 840 )
New value will show same figure
Use up/down buttons to change revs and when happy press 'Test' to see if ok
If ok then hit 'Save' and close otherwise fiddle around with revs and test until happy.
"If like me you are bothered with rough idle/tickover use Mike Fosters guide(above) to turn revs DOWN,
yes that's right turn them down for a while I have been turning mine up (thanks Ewan)with little improvement, to my surprise I have just
turned rpm down to 800 rpm with INSTANT improvement ,
It has only been 10 mins so I guess time will tell"