What do I have to remove to install a fuel injector on # 1 cylinder? on 1993 Infiniti J30

It was diagnosed with a failed injector on # 1 cylinder

Asked by for the 1993 Infiniti J30
The upper intake manifold comes off, the injectors and fuel rail come off as an assembly. Replace the injectors you need to replace; replace o-rings on all.

If you have not done this job before, have a pro give you guidance. You would not want to make a mistake here with the volatility of fuel components.