I've done some testing and worked out the find/replace doesn't seem possible so I think a macro solution is going to be required.
Code:
Sub RelocateCitations()
Dim aFld As Field, aRng As Range
For Each aFld In ActiveDocument.Fields
If InStr(1, LCase(aFld.Code), "citation") Then
Set aRng = aFld.Result
aRng.Collapse wdCollapseStart
aRng.MoveEnd Unit:=wdCharacter, Count:=-1 'to get in front of CC
aRng.MoveStart Unit:=wdCharacter, Count:=-2
If aRng.Text = ". " Then
aRng.Text = " "
Set aRng = aFld.Result
aRng.Collapse wdCollapseEnd
aRng.MoveStart Unit:=wdCharacter, Count:=2 'to get after CC
aRng.InsertAfter "."
End If
End If
Next aFld
End Sub
In my version of Word 2016, the citations are all fields inside Content Controls. The CCs add a level of complexity that require extra lines of code to move the ranges. If your document doesn't also have the CCs then you may need to adjust the macro slightly to work.