Screws to increase the idling: where exactly?

[dorchester]

As in the title, I need to increase a little the idling because it's a bit low and the engine is stalling sometimes (the ignition part is fine and a brilliant job has just been done) and my mechanic is 30 mls far from home. He told me I've just to turn clockwise a quarter turn but I don't want to make a mess and the Rover maintenance booklet tiny sketch isn't very helpful for me at least. A good precise sketch or pic would be very gratefully welcome. Thanks a lot.

[Phil Nottingham]

Photo posted on FB

[dorchester]

And a very good one so crystal clear it was easy for a numpty to do that (easy) job. Now the idle works fine without stalling.
A big thank you to you Phil and all the other contributors.