To get or change a Roblox Display Name, you should first log in to your Account Info page under Settings, then select the edit button next to the Display Name entry above your Username.

Roblox allows all users to change their Roblox account's display name in the account settings without spending a dime. Here's how to do it.

Steps for altering your avatar’s appearance in every Roblox experience, from adding and removing items to changing your skin ...

The process for changing your display name on Roblox is fairly simple. Here's a full breakdown of how you can change your display name in Roblox.