Complex sentence: Skírnir details that the thurs's name who will own her below the gates of Nágrind is Hrímgrímnir and that there, at the roots of the world, the finest thing Gerðr will be given to drink is the urine of goats.
Split into simpler sentences: Skírnir details that the thurs's name who will own her below the gates of Nágrind is Hrímgrímnir. Skírnir comments that there, at the roots of the world, the finest thing Gerðr will be given to drink is the urine of goats.