My question involves a child custody case from the State of: MN

50/50 joint physical and legal custody CO. A little background information. Orginal CO that we have says that niether parent can move more than 30miles away from each other to keep our current schedule of Wed.-Sat. Sun-Wed. due to school distances from homes etc. Well Mom wants to move over 45miles away about alittle over an hr from my house where daughter will be attending school next year. This may sound familiar to some of you because I posted before but this question is going to be different. Mom called out of the blue and decided that she wants me to have our daughter Sunday 6pm- Friday 6pm every week and one weekend a month and she have other three weekends. from Fri. 6pm-Sunday6pm so that she is allowed to move. Holiday schedules would stay the same. And summer I would have the weekends and she would have the weekdays.
Couple of questions: How do I go about getting paperwork for this? What kind of paperwork do I need to get? Signed off on parenting schedule in detail? What if I cannot get her to chance the CO and wants an agreement between just the two of us?
Can she switch it back after I allow her to move if we have an agreement on this schedule? I want to make sure she spends as much time as she can with our daughter, but I also want our daughter to have stable environment and moving all the time is not good on her as I plan to stay in the same place for a very long time so I don't think that switching would be in our daughters best interest if we arrange this schedule unless if her mother moves back to the area of the school district.
I guess my questions is how do I go about proceeding with this in the best possible way? I plan on contacting my lawyer about it, but our case is over 6 years old and hasn't had alot of time to chat with me when I had questions before. The next appointment I can get in is a couple of weeks away. Can any of you give me some advice? Thanks.