*Greetings fellow mortals,*
Here is a small guide on how to change your PBE username if the login page asks you to do so. I don't have the issue myself so I cannot say this small guide is fool-proof. It seems to have successfully helped about five people so far though, so I have decided to make a separate thread for visibility. If you have any questions, please don't hesitate to comment, I will do my best to help out.
Disclaimer: I am not a Rioter, nor am I affiliated with Riot. Guide is subject to change.
*Last edited: 26th of December 2019. Riot released a Nexus post that included some Username questions, I have added these to step 0.*
#**__0. Must you do this?__**
**__YES, YOU MUST.__** The Riot Support article mentions: [on January 22nd, 2020, you’ll no longer be able to sign-in with your old name to play any of our games. You can, however, still sign in to change your username. Just remember, you won’t have to change anything if your name is already unique!](https://support.riotgames.com/hc/en-us/articles/360037264394-Riot-Accounts) (link to Riot Support article).
26/12/2019 update: an [Ask Riot](https://nexus.leagueoflegends.com/en-us/2019/12/ask-riot-usernames-and-senna/) was released on why the change is necessary, and why you cannot keep your old username over someone else.
#**__1. Make sure you have a verified e-mail address on your PBE account.__**
You can check/change the e-mail by going to the PBE boards → ensure you log in to your __**PBE account**__ → top right corner of the boards (your name) → settings. [IMAGE](https://imgur.com/a/r3DU1d50).
If there is a verified e-mail address that is not yours or that you can no longer access, you must go to Riot Support and ask them to help you change/reset the e-mail: go to Riot Support (bottom of every League page, or just google Riot Support), log in with the **__live account__** that your PBE account is linked to. Submit a ticket/request on "Account Management" or "Technical Issues." Do **__NOT__** create a ticket on account recovery (you need to be logged out for this and PBE isn't a selectable region). Within the ticket, specify you're talking about a PBE account and request help changing/resetting the e-mail. You might need to proof ownership of you live/PBE account. Riot Support takes about 2 business days to respond, so don't wait too long doing this.
#**__2. Go to the link from the message and login. If the link doesn't work: https://update-account.riotgames.com/__**
**__BE SURE TO LOG IN TO YOUR PBE ACCOUNT (SET THE REGION TO PUBLIC BETA). OTHERWISE IT WILL CHANGE YOUR LIVE USERNAME.__**
**__I ALSO RECOMMEND YOU USE AN INCOGNITO/PRIVATE BROWSER, SO THAT THE WEBSITE DOES NOT ACCIDENTALLY RECOGNISE TO YOUR LIVE ACCOUNT.__**
If the link doesn't work or if the website crashes (or you get “Yordles got bored waiting for you”) → use an incognito/private window OR use a different browser altogether (seems that Edge works, but Firefox doesn't. Mac users: Safari works).
#**__3. Change your username.__**
Change your username, you should receive instant confirmation that you can login with your new username. Seems PBE has some login loading issues, please be patient while the system logs you in. You will also receive a confirmation e-mail.
I hope this helps. Again, if you have any questions or run into any other issues, don't hesitate to ask. That's what the thread is for.