Mini Kaze 60mm in Thermaltake Element-S case
 

I am trying to attach two Scythe Mini Kaze fans to the rear of my Thermaltake Element-S case. The screw openings in the case are a factor 5 larger than the screws the fans came with. Am I left to my own devices to figure out a DIY solution or is there a solution I am not seeing.

@ the moment I have a total of 7 fans running together with a fan-controller so the PC is not running hot. (20cm/14cm/2*8cm/GPU/PSU & CPU fans) ;)