How do adjust the idle on a Toyota Dolphin Mini-Motorhome

My 84 Toyota Dolphin Mini Motorhome did not pass smog.  High HC at Idle.  Prior to the smog, we fixed an exhaust manifold leak and after that repair, it's idling rough - and for the first time in the 5 years I've owned it - it didn't pass smog.  We think the idle needs to be adjusted - and we don't have the tool needed.  1) do you think adjusting the idle will help reduce the Hydrocarbons 2)  If the idle needs to be adjusted - any ideas where we can get the correct tool?  3)  Any other suggestions will be appreciated