I can offer a tip: Don't try to do a word-by-word translation. The object isn't necessarily to translate it from English to ASL. It is more like translating it from hearing to Deaf.
Take the concept of each verse and make it visual. ASL has the advantage of using 3D space and being beautifully visual. Take advantage of it as much as you can and try to express the concept in ASL, not each word. Try to separate the two in your mind.
For examples you can watch ASL songs on Youtube. It might give you some inspiration.
Edit: Oops, I type too slow. Do you have a textbook to learn to gloss? (If so, is it green?)
