Well, in that case the safe thing to do would be to make your own submod. I normally adjust the copy of the SVN I keep but that's because I'm lazy. A submod is really a much better thing to do. First, make sure you have notepad++ or any other high end text editor. If you haven't had to download a text editor for some weird file, you probably need to go get one.
The tldr of that is first you want to take a .mod file, copy it, paste it, rename it to something like 'ekbloodline', open it, and then either edit the sections to set it up correctly or just blank it and add
Code:
name = "Elder Kings - Bloodline Ambition"
path = "mod/ekbloodline"
dependencies = { "Elder Kings Dev" }
Assuming you use the SVN. Your dependency should be the "name =" section of the ek .mod you use. Make a folder in your mods folder (same folder as eksvn) with the same name as the path.
From there you need to create the various folders necessary to maintain the folder structure. Without going into a step by step of how to make this exact submod, you start with the ambition folder and file which should /ekbloodline/common/objectives/<file name>. For the file name I recommend something like ek_ambitions_bloodline.txt. Copy the base ambition which is located in /<ck2>/common/objectives/00_HF_ambitions.txt (search for forge_bloodline) and add it to your new file.
From there, what you want to do is basically run down everything in that ambition and copy it over to your submod while creating the folder structure as needed. You'll need events and localization and gfx files and so on. If you're having trouble finding something in particular, you can probably ask in the modding quick questions thread. Rather than taking everything in a text file, I recommend opening it, finding the exact event or what have you you need, then placing it in a new file in the submod.
For reference; you need a gfx file for each bloodline and for the ambition (ambitions MIGHT have a default gfx file, but I don't remember). You don't need anything for the variables or flags. You need every event mentioned. If an event refers to a gfx file or an image file you don't need it but it looks nicer. You need localization for every bloodline, for the ambition, for every event and for every custom tooltip. There may be something I'm forgetting so be diligent. I believe you should be able to run this through the validator which should give you an idea if you're missing anything (if you don't have the validator, its somewhere in the base user mods section).
When making localization files (really, its good practice for any text file. I haven't had trouble with .txts but you never know), I recommend copying a localization file and blanking it to make sure you have the right format and everything.