Banjo fitting removal

Probably Not, but it would help if we had an idea about which Banjo Fitting you are repairing.  ???
Every installation is different.

Off the top of my head the only Banjo bolt in the oil system is the one off the bottom of the engine. If you take off any oil fitting you can mitigate an oil purge by just blocking the oil loss when you remove a fitting. You should only lose a very small amount. I use rubber corks, but you must be ABSOLUTELY sure to remove them when you put things back together. I have a red string on the end of my rubber corks to make sure you never accidentally leave one in place.

I put in new copper rings and it wasn't the problem anyway. I did not purge it but what happens if it needs purging what should I look for?

That banjo fitting on the bottom of the engine can be left completely open during an oil change if desired, to help with draining all the oil out of the crankcase. It does not need to be kept full. In fact, when you purge, that hose is led to an open container. No worries, remove and change the copper washers.

Thanks for the help. I think the leak is above the banjo from the push rod tube oring. not a 10 minute job.