They're requested in the Profile Edit Requests Section.
To request any changes, you can either donate and receive the special benefits infinitely and immediately, or you can work your way up and meet the requirements. Below are links with more information on the matter. Read all of the stickies in the section for more information
https://www.mpgh.net/forum/showthread.php?t=448187
https://www.mpgh.net/forum/showthread.php?t=455710