The DRAC card allows you to remotely manage the physical hardware including power the machine on and off, remotely see the machine post, etc. You’ll want to leave it connected.
Just connect a network cable to it, and the next time the server reboots configure the card with an IP address and a password. You can then log into the card using your web browser by simply browsing to the IP address which you assign to the card.
It is a very handy feature which lets you do pretty much anything to the server that you need to without actually touching the server.
You paid a couple hundred bucks for the card, I’d recommend using it and not removing it.