The fitment of the Collector requires it to be slid into the end of the four Primaries. There is a risk of the Primaries being held too loosely by the caphead bolts into the engine block that they sag and incur the side skin. It it helpful therefore, to have reasonably finger tight. the second step is to get the tension springs ready for fitting. Chris Collin's detailed build blog provides a great process and description to open up the radius of the two hoops within the springs such that they fit the hooks on the Primaries and Collector snuggly. This is very helpful since a good fit means the springs can be fitted easily.
The springs are disassembled by pushing the two hoops back through the spring. Once out, the hoops were opened wider, but a screwdriver shank was also pushed down into the radius to provide a larger bend radius. The hoops were then re-fitted to the springs which are then ready for fitment.
the Lambda probe was then screwed and tightened into the Collector and the four input tubes of the Collector were then sprayed with lubricant. The Collector was then lifted into position onto the Primaries. Three of the Primaries slid a few millimetres into their corresponding tubes on the Collector but the fourth was not aligned. Loosening the retaining bolts on that Primary allowed it move sufficiently to engage properly, and the Collector slid home fully onto all the Primaries.
The crux move is then to compress the springs in a safe and manageable way to allow the spring hoops to fit over the end of the hooks on the Primaries and the Collector. Collective wisdom is to use 3 or 4 tie-wraps for this, and one by one they can be tightened by hand to sufficient compress the springs, which were then slid over the hooks. The tie-wraps were then cut. However, at this point, one of the springs did not engage correctly (see the photo). It had expanded sufficiently to be removed from the Collector, so new tie-wraps were fitted and tightened. This created enough space to realign the hook, and to engage correctly once the tie-wraps were cut again.