I don't know if there is a think as Mormon Divorce. A couple that has been civilly divorced or had there marriage annulled, can submit a request to the First Presidency of the Church for there Eternal Marriage to be loosed (or dissolved.  
 
I don't know the details but I do know that you will probably have to be counciled by your bishop, then your Stake President.  
 
At that point the Stake President would probally submit the request to the First Presidency, who will consider the matter, and seek the guidance of the Holy Ghost.  
 
Only the First Presidency has the authority to undo an eternal marriage, but as far as civil divorce goes that is up to the locality not the LDS Church.  
 
The Church does have a strong stance against divorce, they always wish to see married couples reconcile instead of separate, but ultimately it's the couple's decision.  
 
The Scriptures say that Christ felt the only valid reason for a divorce was infidelity.