No idea sorry. Would depend on your existing settings. I would expect that you would have to change both Supervisor and Nginx. So…
In terminal
Nano/Vim the config files and see whats going on.
Make a duplicate of the config files suffixed with OLD or something.
Follow ERPNext guide.
Restart Both Services.
Cross your fingers
If everything is offline delete new config files and remove OLD suffix from back ups
Restart Both Services.
If everything is STILL offline… I never gave you this advice… Sorry about that…
But I bet that you are glad that you had (verified and tested) snapshots of your VPS because that advice that system19 gave you screwed your whole server.
Good Luck