Have him/her monitor all your phone calls just in case someone tries to call you and try to get you to buy something or your drug dealers calling you to find out why they haven't heard from you. Explain to them the severity of the symptoms included in withdrawal so that they can assist you and continue to help you get through it. Never keep yours feelings bottled up, it will only cause more problems. Make sure that the person that you choose for your buddy system is trustworthy and is sincere about helping you. Make sure that the one you choose is someone that you can talk to about anything in your life and preferably is someone that you have known for many years. So even when you are at your lowest peaks, remember that they do not have to help you and that they chose to do so. Most of all, remember that they have feelings too. And warn them in advance that you are going to be moody and to not take anything you say during withdrawal seriously.

TL;DR in Vietnamese:
Nếu bạn nghiêm túc về việc cai heroin thì phải tìm một người bạn sẵn sàng hỗ trợ. Hướng dẫn những người bạn đã chọn. Phải giữ tâm trạng lạc quan mặc dù cảm thấy như cuộc đời đã kết thúc. Nhớ rằng người bạn đó chưa từng giúp đỡ bạn trong chuyện này.