So the big difference is that gasoline is a terrible lubricant. Diesel injection pumps and injectors are lubricated by the fuel itself. So running them on gas long enough can destroy them. However, running them on a high enough concentration of gas just means the engine won't run, so you might have gotten lucky in the sense of having so much gas in there that you decided to shut it down immediately vs it running 'ok' and continuing on for hours..
I would just do the best you can to flush it out, and try it and see. Good chance it's ok.
Cracking the line to the injectors is the best you can do as far as bleeding but you CANNOT just 'hope it drains back'. You need to drain the tank, drain the filter housing if it's a serviceable element, totally replace the filter if it's a spin-on filter, prefill the new one with diesel, and crank the engine until the injection pump has pushed all the gas out of the leaking injector lines until you get diesel leaking out of those fittings, then tighten them down again and try to run it, preferably at idle until it seems totally normal.
If your mechanical pump has a primer function you could use that to help you purge some of the gas. Many don't have it. If you have a compression release you could use that while cranking to ease the load on the starter and battery while you are just pumping/purging fuel.
, change the fuel filter, open the filter cock, then crank the engine until fuel comes out of the fuel pump and close the bleeder valve, and the loosen the injector (or open a valve) conncectors one at a time while cranking until fuel spills then do the remaining two and hope all goes well. THank you all very much for the helP!!