Engine Cover . What Type of Bolts hold that plastic cover on the engine? 2006 Aveo

Can someone tell me what type and what size are the bolts/screws/ or whatever they are called. That holds the plastic cover over the engine, that says 'Ecotec' on it.
I need to remove it to change the spark plugs, but I don't know if they are Allen bolts, Star bolts, Hex bolts, I don't even if any of those are the right names.

I CALLED a Chevy parts dept. here in Ft.laud. assuming they would know...NOPE! They don't know crap. It isn't listed in their order book, to order parts. I asked for ALL Aveo years, and was told it doesn't say what they are, let alone the size. Can someone tell me what they are, and the size?

So I can change the sparkplugs and the plugs to. I think there are 4 or 6 of them holding the plastic over on. Hope this is clear, the plastic over that covers the engine, the oil fill hole, goes through it.

Thanks for some help.

Its a hex key, forget what size.

yeah hex/allen is what theyre called. theres 4 total in my 06 aveo. you can get a set almost anywhere that sells basic tools for cheap. i got a nice set at harbor freight for like $4