How is Recollection of peace (upasamānussati) practiced? Out of the 10 recollections in the 40 Kammaṭṭhāna how is upasamānussati practiced to the level of Jhana?
One should begin by reflecting on the qualities of nibbana, according to the Buddha's words:


  “Bhikkhus, in so far as there are dhammas, whether formed or unformed,fading away is pronounced the best of them, that is to say, the disillusionment of
  vanity, the elimination of thirst, the abolition of reliance, the termination of the
  round, the destruction of craving, fading away, cessation, Nibbāna” 
  
  A II 34 (Nyanamoli, trans)


Practice most likely involves a mantra for each quality, for example, "madanimmadano" (disillusionment of vanity).

According to the Visuddhimagga, upasamaanussati doesn't lead to aapana samadhi, only upacara samadhi:


  As he recollects peace in its special qualities of disillusionment of vanity,etc., in this way, then: “On that occasion his mind is not obsessed by greed or obsessed by hate or obsessed by delusion; his mind has rectitude on that occasion, being inspired by peace” (see VII.65, etc.). So when he has suppressed the hindrances in the way already described under the recollection of the
  Enlightened One, etc., the jhāna factors arise in a single moment. But owing to
  the profundity of the special qualities of peace, or owing to his being occupied
  in recollecting special qualities of various kinds, the jhāna is only access and
  does not reach absorption. And that jhāna itself is known as “recollection of
  peace” too because it arises by means of the special qualities of peace.
  
  Vism VIII.249 (Nyanamoli, trans)