Legal Question in Real Estate Law in Michigan

If you want to take over the project, and be entitled to the assets and any profits, since you are the primary investor now, you'd need to have this "modified agreement" placed in writing, so that your partner(s) did not come back later and claim an interest in the property, when it was you that put in most of the money. The documents in place now, if any, likely don't require you to put in all of this money, so if you do without anything else in writing, that's your choice, but the partners would still have an interest in the property.