I'd say get them fitted but if you're good with those sort of things do it yourself. If you've got your own springs then you may have the same problem I had...which was that garages don't like fitting springs they don't supply. They're quite happy if they can charge you expensive prices to buy the springs and then have them fitted. But if you bring your own they don't want to hear about it. I must have checked with 10+ garages and not one would do it the moment I said I had the springs. In the end I got some help from my Dad and we did them. My Dad is much better with these things than I am but he is no mechanic and it took us a whole Saturday to do. I then took it to a garage and got them to align the wheels and all that. Charged me £50 for that which seems expensive but oh well.
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Performance Blue 07 ST (Naked). Full leather heated seats, electric folding/heated mirrors, factory fitted privacy glass, bluetooth, voice control, mp3 connectivity, auto wipers & lights, rear parking sensors.
Eibach lowered 35mm
Mountune MP165