ShowRaceMenu
Brings up the menu which allows the player to choose a race.
WARNING:
1) Any racial perks will be reset to those of the new race, if a new race is chosen.
2) The player's attributes will be reset with racial bonuses reapplied. Any increases from levelling up will be lost.
3) All Minor skills will be reset to 5.
4) All progress in all skills will be reset.
Therefore, this command should not be used lightly! To pick a new race, these changes must be accepted, but to change the player's appearance without changing any stats, here is a workaround:
1) Open the console (usually with ` or ~) and type showracemenu and press Enter.
2) Don't close the console... leave it open and make your changes.
3) When you're done, don't click the Done button. Instead, press Esc to bring up the menu and Save into a new (recommended) or existing slot. You won't be able to save via the console.
4) Quit Oblivion from the menu or with qqq in the console (Optional, you can always just load straight from the menu).
5) Restart Oblivion and load your save. Checking that your player stats are the same would be a good idea before overwriting any other save slots.