How to delete unwanted music from my iPhone 4S?

I recently got a handed down iPhone 4S, and all of the previous owners music was on it (which I dislike) and I have no idea how to remove it. I have synced my phone with my iTunes and all of my music has been added to my phone but all of the music from before hasn't been added to my iTunes.So, how do I remove it from my phone?

How do I get iTunes on my iPhone 5 without paying is my?

Try going to Settings > General > Usage > Music. Tap Edit. Then, tap the minus for All Music. When the Delete button appears, tap it. You may have to sync up your music again to re-gain it or download it from the iTunes Store. If the music from before is still there, try deleting all data and settings. You will have to re-download everything, but it's worth it either way.

You go into music and find whatever music you want to delete. Then you slide your finger next to the artist, album, ect. That you want to delete. A little red button will show up that says delete on it in white letters and you just have to click on it

That was easy, I spent 2 hours trying to figure it out and this took