Help with User reg solution pack

I have a website which is already running , but need to have user login added to it and give each user different privileges …I came across this website and though , getting this will be much better then learning PHP from start ,,,, I guess I was wrong

After 2 weeks I am still nowhere and more confused then I was when I started playing with this …
I designed many (static) websites even some flash ones and basic flash games… and god knows how many little gadgets like this I used before like pre-loaders etc … But I don’t seem to be able to figure this one out
I must be a complete Idiot for this “User Registration Solution Pack” is meant to be easy and simple to use, with no need for coding…

I find tutorial extremely wage, and hard to follow , its more like a manual without logical order as if it was written as a reminder for someone who already knows what he is doing … but for a noob like me… this is a hell

At this very point I am extremely frustrated and on the verge of nervous break down
So Please HELP I beg you help me how to put this into my website PLEASE
I desperately need a step by step tutorial that make a sense