You need to get the plug and a good length of wiring off a scrap facelift mk1.5 focus

Then basically its cut the plug off your mk1, as close to the plug as possible leaving lots of loom and get as much loom as you can with the headlight plug you get off the scrap car, then its just a case of matching the colours up.

Mk1 Wire Colours

Near Side:

Main Beam - green/black
Direction Indicator - blue/orange
Headlight Levelling - blue
Direction Indicator Earth - black
Dipped Beam - green/orange
Sidelight - orange/blue
Main Earth - black

Offside:

Main Beam - green/orange
Direction Indicator - blue
Headlight Levelling - blue/red
Direction Indicator Earth - black
Dipped Beam - green/white
Sidelight - orange/green
Main Earth - black

Mk1.5 Wire Colours

Near Side:

Main Beam - green/black
Direction Indicator - blue/orange
Headlight Levelling - blue
Direction Indicator Earth - black/Yellow
Dipped Beam - green/orange
Sidelight - orange/blue
Main Earth - black

Offside:

Main Beam - green/orange
Direction Indicator - blue
Headlight Levelling - blue/red
Direction Indicator Earth - black/Blue
Dipped Beam - green/white
Sidelight - orange/green
Main Earth - black

As you can see most of the colours are the same, the only thing you have to watch is the orange and green wires, i wired mine up and the sidelight on the drivers side wouldnt work, the fuse was fine, everything, there is 2 orange and white wires on the drivers side headlight, one for sidelight, one for main beam, id got them wrong way round switched them over and it worked fine.

All the wires are the same so its just match the colours up, apart from the indicator wires they are different on each side, but just follow the guide as above and match the colours to the corresponding function on the headlights.

I just spade connected mine, depends how fussy you are with your car, if you do decide to spade/bullet connect them id put some vaseline on the connections and then insulation tape them up