Slightly embarrassing STI problem (pun)!

I've got some shimano Xt 8'speed STI's for a beast I'm building. Problem is that I can't find how to replace the gear cables, do you have to unscrew the bolts on the underside? These are the shifters: https://www.google.co.uk/search?q=shimano+xt+8+speed+shifters&oe=UTF-8&hl=en&client=safari&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=w6-zUMtqhZXRBYH5gcAB&biw=768&bih=928&sei=xq-zUOHbGaiR0QXp6oFg#biv=i|12;d|YNkEHN88efjDAM:

Any help would be much appreciated, and please forgive the retardation, first time building a flat bar bike. Cheers

Owen

I had some with a little screw on the other side, follow the path of the cable to the other side of the box

yep, unscrew the plastic screw opposite where the cable goes in, and with the lever in top gear push the inner and it will come out from the hole where the screw was.

I've in screwed all the screws that could be described as opposite the cable entry, could you be more specific, sorry to be a massive tit. Cheers

scroll down this link > http://www.parktool.com/blog/repair-help/shift-levers-shifters

On one side of the housing, opposite the lever is a place where the cable goes in. The housing is sort of round if you look underneath, as this is where the drum sits that pulls the cable when you press the lever. Under that lever, and on the opposite side of the round bit is a screw. Imagine looking into the hole where the cable goes. You would be able to see daylight if that screw wasn't there. You don't need to undo the screws underneath that hold the housing on (these are little tiny screws that go upwards)
It is a large plastic screw that has a crossed slot for a screwdriver, and you may well lose it as it is short and falls as soon as you undo it.

you can see it in this pic, opposite the gear cable

Fantastic cheers mate, really appreciate it .

Owen