How i Can Edit this Macro Code

I have used this Macro code in my Excel File. Now i want to edit this code to able i can change it password with a button to load a forum contains Old password, New Password and Confirm New Password fields.

Private Sub Worksheet_Change(ByVal Target As Range)
If Intersect(Target, Range("B7:D9")) Is Nothing Then Exit Sub
ActiveSheet.Unprotect Password:="Password"
Target.Locked = True
ActiveSheet.Protect Password:="Password"
End Sub