So I was able to spend some time playing around with this last night. There is an app out on the store called Health Sync. It has a $. 99 subscription per 6 months. Its only purpose is to sync from S Health to Google Fit. You can try it free for 7 days.
If you want to then get it to MyFitnessPal you can use Under Armour Record to sync between Google Fit and MFP. Hopefully someone writes a better solution but this is the easiest I've found so far.