Often times, as the expert, we will feel that our way is better. Talk to the hiring manager about your ability to overcome that thinking, and follow instructions that you've been given, despite your desire to do your own thing.
"If I were given a recipe to follow, but felt that my method was better, I would still follow the recipe that I was given. It is important to be flexible. If I felt comfortable enough, I would probably make the recipe using my own method and ask my boss for feedback on the end result. Perhaps they would like my way in the end, as well!"