It should be similar enough to work but not the ideal method.
Is the 580 brand new? If it's not, try it in another machine.
IDEALLY you will put the 270 back in, install DDU, run DDU in safemode with the option to clean and shut down.
unplug computer from power
change gpu
plug monitor into gpu port
Restart
Install latest driver.
Restart
ASUS TUF X570 wifi, AMD Ryzen 5 5600G, ASRock 6700XT Challenger, Antec Truepower new 700w. 32GB