Deleting songs from mp3 player. I just bought a mp3 player made by spi. I transfered music into

Question

I just bought a mp3 player made by spi. I transfered music into the correct folder to be put on the mp3 but deleted some songs that i didn't want added. Somehow, every song was added anyway and now i can't figure out how to get them off. It won't let me just delete the song while in the folder, so how do i get them off the mp3?