How to transfer my iTunes music from one user account to another?

I got my iPod touch for my birthday 2 years ago, I set my iTunes account up on my grandpa's Acer laptop. My grandpa now has himself an iPhone. I do not want ANY of my music to go onto my grandpa's phone.(He might flip) I set up my own user account on the same laptop, but now I need to know how to get all of my iTunes music off of his account and onto my user account. Once i have that done can I delete the iTunes icon off of his account and it will still stay on mine?

Not exactly sure. Why not set him up with his own user account. So he starts fresh and you keep the one you've been using.

Its in the options when you close the acc, itunes is a ram hug big time it wants to take over your burner, as well as file defaults, also, use iMesh you can download record & burn on the fly. Now you know pass it on