Advice on Rehab Partnership

[Beau Guidry]

I have a friend that owns a house that needs renovation. He tried to sell it as is but is not getting the offers he wants. He would like to partner with me to do the rehab where I would put up all the money and manage the construction. We would then split the profits selling it as an attractive remodel.

How should we split the profits? 
How can I ensure I recover the money and time I put into a property given that I don’t own it?