I ordered the parts to do this when my clutch master cylinder failed about 4 years ago. They didn't arrive until after the hydraulics were sorted so have been sculling around in the dash until today. Finally decided time had come and it turned out to be a pretty straightforward job thanks to the tip to pretension the spring and hold with cable ties. With this method there is no need to hold the pedal down when fitting.
110 Defender. Year 2000
Parts used:
Britpart spring EDP7510L
2 x bush DCP3212L
1 x U shaped saddle described as Bearing CLP3180
All 4 items also available as a kit EDP7510LBPK from Rimmer Brothers amongst others.
First job was to remove finisher plate that hides the top of the original spring. 3 screws at the bootom of the vinyl panels.
Next unbolt top of spring, remove the plate that retains it and replace bolt. Remove other end of spring from pedal.
Fit 2 plastic bushes to bracket and saddle to clutch pedal.
Compress spring in vice. Ideally place rag over it to limit flight and injury if it slips and pings out. I placed zip ties around the spring legs and tightened them at the same time as tightening the vice. The spring arms need to be pulled together until they are at least parallel to stop the ties sliding down.
Fit outer ends of the spring into the bushes. The coil of the spring should end up at the top.
I ended up with at least a quarter inch gap between the middle of the spring and the receptacle / bearing on the pedal. Lined up the spring so that it was immediately in line with where it needed to be and cut one tie. The other tie broke and the spring ended up nicely in place.