Step 1:  When someone in the church learns that a priest is being or has been accused of any sort of abuse, that someone in the church calls the police.  Not someone higher in the church.  Not another priest.  Not a monsignor or a bishop or archbishop or someone else in the hierarchy.  They call the police and report the abuse.
Step 2:  After the police are called, the person accused of the abuse is removed from his position until the police investigation is concluded.
Step 3a:  If the accused is tried for the alleged crime and convicted.  Regardless of the sentence, that person is removed from his position and excommunicated.
Step 3b:  If the accused is tried and found not guilty, that person is removed from his position for one year - retreat, counseling, whatever - and returned to his position, with the approval of the regional archbishop.  This approval cannot be delegated to anyone junior to the archbishop. 
Step 3c:  If there is insufficient grounds for a trial, the accused is removed from his position for three years - retreat, counseling, whatever - and returned to his position if deemed appropriate by the regional archbishop.  This approval cannot be delegated to anyone junior to the archbishop.  
Maybe these steps should be modified a bit depending on location.  But in the US, sexual abuse is a crime and should be addressed first, but not exclusively, by the civil authorities.  Internal actions are secondary, but no less important - thus the suggestions for internal responses.
Folks, this is not difficult.  Sexual assault is bad.  Sexual assault cover-up is bad.  Doing the right thing, even if it took 2,000 years, should be pretty damned easy.  If it isn't, then the church - or any religious organization - has no place in civil, or civilized, society.