I think you can ask a high ranking BrokenLens Staff Member to change it for you, try asking one of them.
BrokenLens Forums
KnightWalker49
Lanima
Name changes on the server require transfer tickets. Unlikely I'll get a free name change on the server.
KnightWalker49
That's unfortunate 
Lanima
Yeah. But if I do get a chance, I could introduce this idea I have.
KnightWalker49
Oh, do tell more!
Lanima
On the server, other players will see my name as what I picked. However, friends can see my current username.
Doubt it will work perfectly as I imagine it.
Doubt it will work perfectly as I imagine it.
KnightWalker49
All I can say is that it may not be necessary, but that's just me. It doesn't hurt to try suggesting though, I encourage you to put your ideas out there!
Lanima
I do put my suggestions out there. Just not some of them because they're selfish ones.