Hi Zag I posted this in answer to another users qusetion a while back i have cut and pasted it below hope it helps , this is the way i went about it.
original post
If its fairly recent sky dish, it should work if you have a universal lnb on the dish if not you will need to replace it , they are really cheap, you should be able to pick up a free to air decoder for under 100 euro. By connecting the coax from the sky dish into it you should receive all the fta channels, bbc1 2 3 4 itv utv film 4 and many more channels. I am not well up on satellite stuff, but here's how i went about it,
I purchased a free to air full system off a company called zintek, on the green hills road, the whole system only cost around 120 euro (and no i dont work for them), I found the guy really helpful there. I hadn't a clue how to set it up , but decided to give it a go myself. I looked at the way the neighbours dish was setup e.g the direction it was pointing e.t.c. After pottering around with the dish for about 1 hour, starting off with the dish pointing downwards and moving it up a notch at a time and then from left to right slightly i found a signal. I had the dish in view of a tv set because the dish was at the end of the garden. I couldnt believe my eyes when i came in and had all the channels and all for free. I dont get channel 4 but i will live without it , when ntl come out and disconnect which i have requested mid december and no sign of them yet!. If you cant have sight of a tv while setting it up you can buy a sat finder for about 15 euro, and that will tell you when you have a signal. For rte i bought an aerial which i placed in the attic and i get rte 1 2 tv3 and tg4 perfect. I can't believe more people don't do it, I do know that there are restictions on placing dishes on the front of the house e.t.c. but i was ok because it is in the back garden.
I am not sure if this is the best way to do it but that's the way i did it , the one thing i didn't do is earth the dish which i heard is a good thing to do, i was talking to an electricial and he said its quite simple to do, so i should get around to it soon.
There is a website called
www.satellite.ie and it has a section on frequently asked questions and i found it quite helpful.
hope this helps