Complex sentence: The first stage extended the terrace covering on the Trinity Road side at a cost of £887 while the second cost £1,300 and involved re-laying all terracing around the track to remedy a design flaw that caused poor sightlines for the majority of the crowd.
Split into simpler sentences: The first stage was to extend the terrace covering on the Trinity Road side at a cost of £887. The second stage cost £1,300 and involved the re-laying of all of terracing around the track to remedy a design flaw that had led to poor sightlines for the majority of the crowd.