Been a while since i've done this but here goes......
Zip the 2 pockets together
At the top of the yoke there should be 2 male snap connecters
Snap these into the two female connectors either side of the zips
Again do the same to the bottom of the pouches
Then my pouches had 2 little straps on the bottom, looks like you could attach a kip mat or something similar.
Unsnap these and they connect to the front straps to complete the daysack.
I think there was a longer strap that went round the middle, i used to feed these round the back to hold both pouches in place and stop them banging around.
I think thats right i always found my daysack a little too tight under the arms but i am quite a big bloke
No pictures sorry as i am at work at the moment, but if you are having any more problems let me now and i'll dig mine out and do some piccies for you.
Hope that helps a bit
"They couldn't hit an elephant at this distance."
Famous last words of General John Sedgwick
May 8th, 1864