My daughter just got out of an abusive relationship and the guy won’t leave her alone how can i get rid of him
Call the police so that she can press charges against him and file a restraining order. Especially if you think she is in any sort of immediate danger, the behavior needs to be reported so that they can take steps to head it off before it escalates further. In general, magic should never be used in place of taking the necessary mundane actions first.
If you’ve gone the legal route and need to boost your efforts, you can look into protection spells/charms, spells that might work towards a peaceful resolution of the relationship, or ones that would simply encourage him to move on. In more extreme circumstances, you could also look into something that would bind him from doing any harm to her.
The Informed Pagan 
I totally agree with doing the police route first. I would add an “order of protection” from the courts has a little more legal power, so look into that. There are several good, easy protection spells out there – along with the binding spells. One I have used that works well is writing the offender’s name all over an egg, wrapping the egg in black thread, then placing it in the back of the freezer. Leave it for a month, then bury it. It basically freezes his actions.