I am about to remodel my bathroom which is very small. The biggest problem I have is the concrete slab is not level and because of this over the years we have had several tolets broken. The only way to level it is to basically raise the toilet a few inches so we can have a level place for the tolit to sit. I know we will need to extend the sewedge pipe up and have a plumber set up for that what I need is how do I make the form and how tall should it be? How do I make the form and does it need to be reinforced with something?

Not sure I completely understand your question. Is you entire floor so unlevel that you want to level it or is the floor around the toilet not level and you want level and smooth it that area? Is this floor a basement or concrete floor or is it a mud base poured on a wooden floor? What type of pipe and floor flange do you have?