Factory reset it, connect to it with Winbox, and when prompted remove the default configuration entirely.
This will disable wifi and remove the IP addresses and all other configuration.
Now, connect it to your PC over ethernet, open Winbox, and go to the “Neighbors” tab. You will see the device listed with its name and MAC address, but no IP address.
Click on the MAC address in the list, and click connect.
Now you can create your bridge, add the ethernet and wifi interfaces to the bridge, configure the wifi interface however you would like it, and away you go. You may briefly lose access when you add the ethernet port to the bridge, just re-connect and it’ll be fine.
You might be wondering how this works without an IP; Winbox does not require the device to have an IP address in order to connect. Only layer-2 access is required, as long as MAC Winbox Server and neighbor discovery are enabled on the interface (the default configuration disables both neighbor discovery and MAC Winbox Server on the WAN port for security reasons).
This is, in my opinion, one of the best features of RouterOS + Winbox; if you have L2 access you basically never have to worry about losing the ability to log in.
[Edit]: And please, please, please don’t use QuickSet. It only ever works on a device that’s got a completely default configuration on it, and it only works once. It causes more trouble than it solves.