I made a function where a sword is attached to my character , but now i want to do the exact opposite , What nodes do i need to use?
Just use the DetachFromComponent node.
When i use that node , i need to also get a reference to the actor which i want to be detached right?
Yep. You will probably need to save a “Weapon” variable.
It’s Detach From Actor. It only takes an actor reference. And it will detach an actor from any scene component it’s attached to.
And, as above, you must keep a reference. Querying components for attached actors is a no-no in BPs (afair).
OK thx 
Thanks