Help Wanted! Does anybody know how to change a blog skin?

it's been ages since i blogged i know. and i really missed doing what i love.

two reasons: busy being a pharmacy student and i'm looking for someone to help me change my blog skin before i start blogging regularly again.

i don't know how the heck do you change the blog skin, say, a blog skin from freeskins.blogspot.com. i saw a number of skins that i like from here and there but i have trouble saving them as my template. can anybody help me out here? i have also visited some help sites and followed as they said but i still can't get what i want.

after i uploaded the new template it said: "Your template could not be parsed as it is not well-formed. Please make sure all XML elements are closed properly. XML error message: The content of elements must consist of well-formed character data or markup."

i'm not a computer junkie so i don't know what xml element is and i desperately need somebody to help me. i'll truly appreciate it! =)