3 different ways
1) if its been a long time, ( like no history or never) I go ahead and remove and open up the IAC and clean it really well and get any kind of grime out so that it works smoothly.
2) if say I had done the IAC in the past few years, then I will just shoot some cleaner in without removing
3) with a bent straw trick spray sea foam in while its running. they sell a can with a bent straw but not all stores sell it
when ever I do valve cover gaskets, I do a good cleaning of the IAC and throttle body while its all off, and soak the intakes to get gook out...why not
the screws although look like phillips heads are JAS and JAS drivers fit better and less likely to strip
last time and I was on short notice, NAPA even had the IAC gasket and the throttle body gasket
also ever notice that TRD has a throtte body gasket and its a big "O" instead of the "D" shape of the stock gasket. The last time I did one I cut it into the "O" but I could tell no difference....maybe it helps if you have a super charger