You need following tools:
Ring spanner/Ratchet spanner 10, 13 and torx 20, 30 and a flat screw driver.
This is for Xantia 1998-2001
1. Begin with remove the protection in front of the cooling fans. It's attached with two plastic screws.
2. Loosen all bolt on the frame above the radiator. All together 6 of them. Hook off the wire for the bonnet opening. Hook off all cables that are attached in the frame above the radiator. Remove the bonnet locks.
3. Loosen the two upper screws for the headlights. Torx 30.
4. Remove the flashers and the circuit connectors. It's a small "threshold "behind/above that you have to push and then try to move out the complete light.
5. Under the flashers and the headlights, it's a small list that must be removed. It's attached with two white clips and plugged under the headlight. Remove the clips gentle and then take a flat screw driver and pry out very gentle. The lists are fragile and can easily crack into pieces. Both sides.
6. Work on from the middle of the headlight. Far inserted beneath, the last torx 30 that holds the headlight is situated.
7. Remove the circuit connection.
8. Look far above, there is a 10mm bolt on each side approx between the headlight and the flashers. A bit above there's a screw-nut on each side.
9. Fold the inner shields in front of the front wheel houses. There are supposed to be inspections hatches but they can be closed due to a manufacture error at the casting.
10. Where the front bumper meets front innershield and metal on rear edge, theres a torx 20 with a space. Further into crosswise it's a long bolt 10mm. It's very narrow to get there with a ratchet spanner so I recommend ring spanner 10.
11. Loosen the bolts under the car and in the wheel house that holds the inner shield.
12. Loosen the bolts that holds the front bumper under the car. All together 3 pcs.
13. Then you can lower everything diagonally down/forward. Disconnect the fog lights.
14. Now the hole radiator is attachable.
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and here is my pic story of radiator fan removal without removing the bumper.