Okay so i bought this quad (2003 trx400ex) with it missing some parts and pieces, one of them being the headlight bulbs.. Got new bulbs, went to install and i feel like i am missing a piece. But looking online, on ebay, and exploded views i dont know what i am actually missing or how these bulbs are held in.

This is what the back of my headlight looks like,

And for the exploded veiws i have,

SO I have #2,3, and 4, which according to the exploded views is all the parts.. Im guessing there is a piece that screws into the back of the housing where the two screw holes are that i am missing?? Or does it fit in some other way?

Thanks!