Ive typed this out before so just copied and pasted it

And its a basic guide.
Fronts
Wheels off.
Car on axel stands.
Unclip any hosing from the strut (brake lines etc).
Disconnect any anti roll bars.
Get the bottom of the strut out of the hub housing (easier said than done on some cars- my Fabia

Punto was easy).
Undo the bolts at the top of the strut- under the bonnet.
Take out the whole strut with spring.
Compress the spring and remove the bolt holding the spring in. This is usually dead tight so I got local Kwik Fit type garage with a whizzy gun to undo it for a fiver.
Swap springs over, cut bump stops (if required) and tighten up the top nut
Re-fit the whole unit back where it came from.
Backs
Get the car on axel stands, use a trolley jack and raise the trailing arm to take the strain off the shocks. Undo the bolt holding the shock on and lower the trolley jack slowly making sure brakelines arent being pulled down with it. The spring should come out on its own, but might need a spring compressor on it. Then stick the new spring in, trim the bumpstop and do everything back up!