Thanks so far for your help, but we having a miscommunication and I try again step by step what I have done.
1. I did used FPCUPDELUXE app to upgrade my installed lazarus copy. (prior it was also installed by fpcpudeluxe)
2. I applied my patch to projectintf.pas inside \lazarus\components\buildintf\ folder.
3. I opened Lazarus and press on rebuild.
4. I test it by creating a new project.
5. I open my webbrowser, writing here that my patch is not getting applied and asking for help.
I really hope that this is clear enough this time