The script is the most difficult part of the journey, or at least I think it is. You need to figure out what works for you and isn't too tedious to write (though it will definitely be tedious no matter what). This is also where any prior skill of scripting and/or manifestation becomes useful, as you will already know how to script in a way that gets you results. There are many different ways to script, and it may seem intimidating at first, but you'll find something that works sooner or later!
For some ideas, you can try writing down what you want over and over again, several times for each detail. Try to go into as much detail as possible for every method you use, of course. Writing things down repeatedly can help get it in your mind and cement it as a fact in the world.
You could also write it out as a diary entry, which may work especially well if you need to plot out a specific scenario that'll happen later. Writing it as if it's already happened can be helpful, again because it confirms to the world that it's a thing that really happened. For things like this, writing a letter to whatever powers that be also tends to work for a lot of people. Writing to the world about how grateful you are for having these abilities or even having the opportunity to gain them can win over their favor and make them think you're truly worthy of your powers.
There are dozens and dozens of ways to write a script, and I haven't even touched on traditional manifestation, which also works wonders in a situation like this. This is where I prompt you to do as much research outside of this site as possible, because I'm just one person. There's too much to say here and you'll be more likely to find something that works for you through your own means, rather than what I can tell you. Both of the methods I talked about have worked for me to varying degrees of success in the past, but I'm not you!