O and X menu buttons wrong way round, how do i change?

I have a white japanese PSP(dunno if that makes a blind bit of difference)but i have noticed that unlike all the other PSP's i have used (3) the circle button is the accept (select) key and the X button is the cancel and back button.... how do i change this so it is the same as everyone elses PSP????? as i have to press the circle button to start the UMD games and once the game starts im back to using X.... i want to select using X all the time.... its really annoying.... how do i change it? can i change it????

some jap games (mgs for example) use o to select. maybe u should buy a uk/us version of the psp. i dunno if u can fix it otherwise.
g

pspset has an option to swap the buttons there is an extremely small risk of bricking ur psp so make sure its plugged in to a wall