H105 installation problem

[SniiKz]

Hello, after getting somewhat close to an end of moving case and some new parts I am kinda stuck right now installing the h105. I couldn't fit on the backplate after trying a little bit of force and enough to pop out one of the "screws" on the backplate. So here I am wondering what's wrong and what to do next? 

Would there be huge consequences if I didn't install the backplate or am I fine without doing so or is there any way to "fix" my problem?

 

Asus P9X79 DELUXE motherboard
Intel BXTS13X (old cooler)
Corsair H105 (new cooler)

 

Also included some screenshots I tried taking, a bit dark because it's late, but hopefully you can see something.

it looks like there's something black covering the holes but there's not any screws there.

 

 

 

This is also my first time actually building a computer so forgive me if there's something obvious I should have done 

 

Thanks in advance for any help, would just like to use my computer again 

[airdeano]

here are the parts of your kit:

 

the jack screws that have the wide 4mm stubby threads and the thin threads are the ones to use.

the fatter 4mm screws into your motherboard plate and the thinner holds the thumbscrews.

 

[SniiKz]

@airdeano Thanks for the help, found out the LGA 2011 standoff screws are missing from the H105 kit which is probably why I'm having a hard time.