It's quite possible that you can't!
Although there are mac distros of apache / mysql / php they are usually for the mac. Anything else and I reckon you'll have a hard time finding a suitable package. Plus in reality who is going to develop php powered sites on such a small device?
My helpful sig has gone because a mod below the administrator gave me an infraction - despite the administrator personally agreeing to it.
If you need any php tips or tricks you can PM me.