आकाशे: from the sky, गणशः in groups, स्थित्वा: staying there, ताम् those, हरिवाहिनीम् Vanara troops, अश्मशस्त्रमहावृष्ट्या: astras, sastras, boulders, हत्वा: killing, यमक्षयम् to the abode of Yama, प्रापयाम: will send

Staying in the sky in groups, we will rain astras, sastras and boulders on the Vanara troops and on killing them, we shall send them to the abode of God of death.