From Reddit: “How is a pagan supposes (sic) to do the abramelin?”
By the power of Metaphor.
You go into it assuming that “YHVH,” “Tzebaoth” and “Adonai” are all metaphors for whichever god(dess) that you do worship, so that when you invoke them you are really invoking your patron deity by another name.
Remember, Dion Fortune once said that all gods are but one God, and all goddesses are one Goddess. Indeed, the Hermetic Qabalah was formulated so that people of different religions could all share in one magical tradition: participants were actively expected to translate the, for example, Egyptian symbolism they encountered in a Golden Dawn ceremony into concepts that made sense to them in the context of their own religion, via the Qabalah.
The modern fancy that you have to stay within the ghetto of your own religion, no matter what, goes against the history of why the western magical tradition was created in the first place.
Source: How is a pagan supposes to do the abramelin? (sic)
Sol Ascendans - The Website of Alex Sumner 
“Should therefore the candidate hear the name of any God, let him not rashly assume that it refers to any known God, save only the God known to himself. Or should the ritual speak in terms (however vague) which seem to imply Egyptian, Taoist, Buddhist, Indian, Persian, Greek, Judaic, Christian, or Moslem philosophy, let him reflect that this is a defect of language; the literary limitation and not the spiritual prejudice of the man P.”
-Liber LXI
“In the true religion there is no sect, therefore take heed that thou blaspheme not the name by which another knoweth his God; for if thou do this thing in Jupiter thou wilt blaspheme יהוה and in Osiris יהשוה.”
-Liber Librae