Redbuilding a system

For long, I have been interrested in a system propose in a French book, called “Le Livre des Non Morts” , the Book of Undeads". This is a book dealing about Vampirism. It is one of the most reference I have know, and probably one of the most efficient in my knowledge, with maybe the exception of Michael W Ford “Akhakharu”.
The book propose a system that use the magickal square of Abramelin (Sacred Magick of Abramelin the Mage), as a system to cast for spells and curses, in a very Left Hand Path way. It also focus on Romanian archetypes, mainly Xalmoxis (an ancient Dacian god); and Vlad III “Tepes” , witch is something quite different from a lot of new grimoires that rather focus on babylonian and sumerian archetypes.
First I will explain the original system to you, then I will talk about my problem with it.

The system propose a nine month period (as in the sacred book of Abramelin), before the practitionner use an invocation of Vlad Tepes to make a pact with him. The goal of the pact is to rely yourself to the “strain” of Undead vampires. The goal is isn’t conscient reincarnation as it can be read with some other method. After death, the practitionner is supposed to be part of that “strain”, and will live true the living adepts .

During the nine month of preparation, the training is:
-Training to vampirism, as decribed by E.A in one of his video and in the Banefull Magick lessons. So draining people every times that’s possible
-Training in Out of Body Experience, many time during the week.
-A a particular ritual called “The calling of blood”, in witch te magician will call the archetype of Lilith, offer her a cup of menstrual blood. Mark each of his chakra with his blood, and invite he in.

Then, after nine month and only then, he will make the ritual to call Vlad Tepes and make a pact with him and all te vampiric strain.

Here is what the problem is to me :
I Have tried the Nine month thing discipline, but have failed and had to take it back from 0, at least three time.
The reasons are various. One of them is the obligation to to the “calling of blood” ritual once per month , a Friday night, at midnight. I’m even working during that period, and when I’m not, there is always my future wife wanting to see me (as week end are the only moments we can have together).
Plus, I’m not a big fan of the Lilith archetype. That’s not a demon I have a great affitinity with.

Now, knowing I practice magick, and particulary vampirism , since at least 2009. I have several questions in mine coming to me.
-First, is that nine month thing a necessity, or should I go straight to the point, and try te evocation for pact right now, knowing that I’m already confident with vampirism, and have convinient results with out of body experience, thanks to E.A btw ?
-If not, should it be possible to rebuild the ritual, using another entity, one that I would feel more in affinity with…and probably one that is not evoked on Friday. I was thinking of Noctulius, from the ONA; I would need to rewrite the Ritual completly, but I think I will feel more presence with the entity than with Lilith (who as for Satan is pretty vague for me).

Can you give me you opinion about that ?
Do you think the nine month thing should be respected as said ? Do you think the process could be efficient wit a rewritten ritual ?

Many thanks for your opinions