The elec connectors come off with a tug - on the clip not the wire! The rail clips slide outwards. When the 10mm rail bolts are removed and the fuel damper pipes loosened, the rail will slide off
the injector ‘O’ rings. If the rail has never been removed it may be a bit of a job, and an injector or two may come with the rail - start at one end and gently prise upwards
The injectors can be removed, or left in the manifold as long as care is taken in the rest of the removal process. Leaving them in leaves less chance of crap going down into the inlets.
Remove all the visible vac hoses and breather tubes.