embed and style external xml data

I like to embed a tumblr blog into my site

using the tumblr api i can get the blog as xml data using

http://(you).tumblr.com/api/read

i like to use css style to style the xml data

i am not an experienced html css xml programmer.

what html do i use to embed the xml data and apply my style?

thanks in progress

Remko van Dokkum