may be something only available to an upgraded member....
but you could always contact Robert, and maybe ask nicely to sort of delete your account, in order to change your username....or he may have another option...
in the mean time, pick a name, and think about it for a month or two.....as it will be your permanent username....
this may be a one time thing, and not something you want to change over and over......
we have a number of Kelly's...and Kelvinator members....could be a nickname as well...it will be yours for a long time...
may be consider KellyKnowsHow....but that might be construed as having a lot of knowledge of machines...who knows, you may be a Jack of all trades, Master of none...anything is possible....as in being able to join at age 11...