hi what we do as a sky empleyee is.
1)cut the outer covering off
2)pull down the wire bradeing
3)now cut the metal sheffing about 5mm from the bottom then pull of the sheffing and the foam/plastic the is covering the inner cor off
4)now screw on the f connector.
if that makes no sense then have a look here
http://www.satcure.co.uk/tech/fconn.htm