Nissan Repair Questions? Ask a Mechanic for Answers ASAP
I show a diagram showing the what appear to be 4 nuts holding it on.
Here are the instructions for removing the radiator and the step for removing the reservoir are included in that,
If it sits in front of the radiator then if you cannot reach those nuts and/or there isn't enough room to remove that reservoir, then I would assume once you remove the nuts from the radiator top mounting brackets, perhaps you could tilt the radiator reward enough to reach that reservoir. If not just continue removing the radiator until there is access.