The suggestions from TNP are rather straightforward translations. The second one (Ko imaš samo ljubezen) is direct translation. In Slovenian, the second person singular pronoun "ti" (expressed or implied) often serves as generalized "anybody" like in French "on" or English "you". Some different translations are possible, of course. For example, Ko ostane samo ljubezen ("when only love remains", skipped pronoun) or Imeti samo ljubezen ("to have only love", infinite construction).