Very simple process to change Will, if you have (or access to) a trolley Jack and axle stands even simpler. As you can see in the photo it's a matter of getting some 5/16" studding and half a dozen nuts and a couple of washers. All available from B&Q or similar.
No need to remove the brake discs or calipers etc. Although access is easier, this is what puts a lot of owners off.
1. Remove one of the lower 5/16" nuts and bolts From the lower plate (1/2" AF spanner size or 13mm Metric)
2. Fit the studding to that side, if you note 2 nuts on top locked together as that thread locks them making a very long bolt) then fit the lower nut and tighten to replace the nut and bolt you just removed.
3. Do the same for the other side of the plate, again tighten the studding nut.
4. Undo the central large nyloc nut and set to one side.
5. Slowly, and about 2 complete turns each, undo alternately the studding lower nuts to relieve the rebound spring pressure. Turn the steering from lock to lock if it fouls the lower lug and it will soon pop through.
6. When all tension is off, take off fully the lower studding nuts, remove the lower plate and change over the rebound spring.
7. Reassembly is as they say a reverse of the strip down, just a couple of turns of compression is enough either side, take your time and it will pull up square. Keep alternating until the lower plate meets the lower lug and the rebound Spring is compressed in place.
8. Refit the centre large nut (no need to replace unless you happen to have one), Nylocs are supposed to be good for 6 remove/refits but some obsess about this, your call.
9. Remove the studding from one side and change for the OE nut and bolt, again your call if you want to replace the 5/16 UNF Nyloc? No need to but I always do for customers as I buy them in bags of 50 ;-). Then do the other side.
10. Spin the steering lock to lock just on case (but it will be fine) there is some coil bind and do a final spanner check of all disturbed nuts and bolts.
11. Shot of grease whilst your in there and then the same on the other side of the car and jobs a good un!
If you hit a snag just shout.