In reply to Taurig:
You won't have any problems with finishing, go out to enjoy and you will, forget the clock.
You mentioned "injury niggles" an indication you are on your limit in training, so take it very easy this last week, there is nothing to be gained (as already said). Walk, jog, rest for the week as your body feels, you will not get any fitter.
This is your first hill race, aim to complete it irrespective of times, enjoy the atmosphere and take it from there.
You're fine, have a great evening.