tatra - on that hill; avinaṣṭa-avayavān - the demons who had been killed but whose bodily parts had not been lost; vidyamāna-śirodharān - whose heads were still existing on their bodies; uśanāḥ - Śukrācārya; jīvayām āsa - brought to life; saṁjīvanyā - by the Saṁjīvanī mantra; sva-vidyayā - by his own achievement.

There, on that hill, Śukrācārya brought to life all the dead demoniac soldiers who had not lost their heads, trunks and limbs. He achieved this by his own mantra, known as Saṁjīvanī.