Changing determined fate?

I am **LDS** and had a discussion in Seminary the other day. Our Heavenly Father is all knowing, meaning he can see our past, present, and future. Let's say that according to Heavenly Father, I am not going to the Celestial Kingdom. He already knows that. How do we change what he already knows? I know it can change perspective for us, but how can we change it for him? **How do we Change our Determined fate based on what Heavenly Father already knows?** God knows the future of what the free-will creatures choose. Free will does not stop becoming free because God knows what will happen. Is this True? If he already knows everything though, how can it be that we make any different choices than what he already knows we will make?