In the case where you really need word for word, like in a theater script…
I would do a memory palace with a station for each line/sentence (whatever subdivision that feels logical to you), with mnemonics for the main keywords and/or for the first words.
It’s not an obligatory step, but that way, you can always know “where you are” in the story. It avoids drawing a complete blank if you lost track, you can at least restart anywhere.
And then the first letter method, to get the rest down (filler words and such).
Then when you’ve learnt it, say it from beginning to end, notice the places/transitions where you hesitate and drill specially these passages.
Explaining the first letter method if you don’t know it yet:
