Minecraft Junkie

please help and without using winrar

You go to your minecraft account, and set the URL to the skin file or upload it.

Google is your friend. Just google minecraft skins.

You will most definitely need winrar or winzip, or any other archive program do do most things so i would reccomend getting it or finding a free alternative. but you do not need it as far as i know, just download it, go to the website, then your profile and select the skin file. And presto you have your very own skin.

You don't need any of those programs. All you need to do is download the file (should be a .png) then login to minecraft.net>Profile>ChangeSkin>Browse>Save (Rough example) And you are done. Here are some websites you could use to find one. (If you don't have one picked already.
http://www.minecraftskins.com/
http://www.minershoes.com/

or if you use skindex you could click the upload button and upload it to minecraft.net then all you have to do is put in your password say yes and your done :/