I'm just curious TP01, has your instructor not gone through any of this with you ??
Ring him or see him if poss to go through a quick run through of what's involved, you shouldn't really need to get this sort of info from here. Not having a go at you, more your instructor for not briefing you on what to expect.
For what it's worth, mine was about 2.5 hours, nav leg 1 to point A, turn onto nav leg 2 to point B. About half way to B, diversion to point C. You have time to do some rough calcs to estimate your heading and ETA so don't panic this bit, nice and calmly does it. (tip: make sure your chart is folded to cover the entire nav triangle, you don't want to end up fannying around with new folds mid-air. Perhaps obvious but can catch people out).
Reach and identify point C, then onto general handling.
I was told I could do it in two parts, break between nav and GH, but I opted for continuous test.
Relax and fly like you do normally, you'll be fine. Good luck, let us know the outcome.