How do I replace a front coil spring on my 2004 Peugeot 307 HDi?

The fact that you are asking this question tells me that you are not compitent enough to tackle this job. Apart from the usual box of tools (spanners, sockets etc.) you will need spring compressers and if you don't use them properly, the spring can fly off like a cruise missile causing severe damage and/or injury. I suggest that you take it to a mechanic as it is not a job the novice DIYer.

The Rusty Sherriff
February 2009