Remove the drawer from the Focus dashboard (pull forward then depress the retaining tab).
File the slot in the rear left corner to make it fit the power lead.
Feed the plug and lead through the hole where the drawer went then put the drawer back in the dash. I have found that the lead fits best when hooked over the slot about half way down the cable.
This leaves enough slack to open the drawer and remove the CD player if needed.
Remove the CD player. I fixed the earth to the earth tag on the CD player and used the Yl/Gn on the CD as the +ve. This is ignition switched so the plug with inbuilt regulator is off when the car is unattended.