How to edit the source code to update at runtime?

So I’ve recently downloaded and set up the github Source 4.19.2 version of UE4 because i needed to expose a variable to ReadWrite in blueprint form. Specifically i needed to make Num Sides of the Cable Component editable in the editor and at Runtime.

Now i’ve got the first part to work (Meaning you i got it set up so that you can Set Num Sides in blueprint) but it wont update at runtime. Im new to working with Source code and to be honest im also new to C++.

So my question is,how do i get it to update at Runtime? I want the player to pretty much be able to Set Num Sides for the Cable Component and then spawn it in.

Any tips?