Hi
I replaced one side (twice ) within a couple of years,as far as I can remember the front bumper has to come off ,the armature and the crash cans in the subframe.I also found it easier with the headlight removed as well.Its not too difficult,just awkward and time consuming.
I used a cheap aftermarket kit the first time and it had play in it within a year.(the bearing seat in arm was not to good,maybe this was cause).
As its such a pain of a job I would use quality parts.
I posted a few months ago about a cheap way of using an new old stock metro upper fulcrum shaft (same asTF ) being sold on ebay for a tenner and using genuine roller bearings, a cheap aftermarket kit for seals and bolts.This cuts the parts price in half.
I already have a new shaft stored away for when I need to replace other side.