You will not require to disconnect the washer stuff to get to the lenses.
Just slip the bumper forward and lay it on a blanket to avoid scratching and swop out the lenses
Just saw this since your last PM.
Sounds like it is your Park Neutral Position Switch.
Remember that when fitting a new one it has to be adjusted before you nip up the bolts.
As what Will has said + run the car with the roof up and get the heater on full hot blast for half an hour to soften the fabric.
Also a fully charged battery always helps.
Did you actually replace the manifolds or just cat back ?
What brand of exhaust parts did you fit ?
How do you know that it is running to rich ?
What year and model is your 350 ?
Did you remember and fit noise reduction anti squeal shims ?
OEM genuine Nissan Brembo pads from the dealer have the shims bonded to the rear of the pad.
Aftermarket genuine Brembo pads have no shim bonded to the rear so aftermarket shims are required.
Same size as the OEM bolt + extra length for the thickness of the spacer.
Make sure that you fit good quality spring washers and that you fit a bolt and not a set screw.
The fronts tend to be very tight sometimes.
As has been said, use a good quality socket that will not slip.
Use a 600mm breaker bar, and get the leverage angle right, and you will be on the home straight.
I would get the bumper off and assess the damage properly.
Was expecting much worse actually.
You must have been almost stopped or the deer was the size of a rabbit.
Alex.