Adjusting the idle speed is not going to affect anything else so you can easily do it yourself. Just remember to 'purge' the induction after each adjustment, ie run it at 2000rpm for 30 seconds, and then measure it.
If you want to accurately set the idle speed, rather than using the rev counter, some timing lights ( strobe ) can be used. Basically you dial the rpm on the light, and when the timing mark is steady you are at the exact rpm ( or double it
)