Taking just the sharp point off is the only way to do it
any deeper will and could hurt the bird.
This is a site that when I signed up I got a really good three part training video on how to get your parrot to accept and have fun with getting a nail trim.
http://www.goodbirdinc.com/
when it comes to trimming the beak I go for putting things in the cage that will wear it down.
If the beak is malformed best to let a avian vet do the trimming.