If your key has stopped responding and you dont have a red key, you will require a new ECU, Code Box with the keys from that car.

If you have lost your keys, then you will need a new ECU, Code BOx and Set of locks with the matching keys from that car

ECU + Code Box
Matching Keys(Red + Blue if possible)
Ignition Barrel
8mm Spanner/Socket
Philips Screw Driver
Lock Set

1 Disconnect the Battery
2 Unscrew the fusebox cover righthand side of the steering wheel(1995 1.1 55s)
3 Remove the small black code box, unclipping the cables first
4 Fit the new code box and re-connect cables
5 Remove the cable from the ECU
6 Un-bold the ECU ( 4 x 8mm Bolts )
7 Put new ECU in and bold back down and connect the cable
8.1 Change the ignition barrel if required
8.2 Re-Connect the battery and fire her up :)

This is my first guide, hopefully first of many.