Soft Tonneau Fitting Instructions

[chickenstrangler]

Hi all, just seeing if anyone has fitting instructions for Genuine Toyota Hilux SOFT Tonneau cover.(2010 Dual Cab Workmate Tub).
I have picked up new cover off eBay but never came with fitting instructions..
It looks pretty straight forward but need to know the distance from top of tub to Securing Button thing. Just dont want to drill holes in wrong spot. Appreciate any info regarding correct placement of buttons on th tub.

THX CS