Is it possible? Hell yeah it’s possible. You can change literally anything about any theme any time you want.
My opinion: It would be WAAAY easier to build your own them than to chop and screw someone else’s.
I speak from experience because I started out just modifying every theme to death and then it dawned on me: It would be easier to build everything to spec instead of going in and changing someone else’s code. And you know what? It is.
Yes, but I want all the functionality that is within the theme. I love the portfolio section. I just need to adjust the header area and the background. And it’s only one page I’m doing, just my portfolio page. I don’t want to redo my entire site.
There are certain cautions you need to take when modifying a Theme directly, one of them is it makes the theme so you cannot update it.
Generally it is better to make a [Child Theme](http://codex.wordpress.org/Child_Themes “Child THeme”) or if it is just CSS changes you could use (if you have it) Jetpack for WordPress installed, the plugin comes with a custom CSS section.
There is more to this, but use a child theme for modifications to existing themes.
Excellent, thank you. I’m researching child themes and Jet Pack.
In your opinion, when I’m setting up the theme on my domain, should I create a subdomain – portfolio.simeonhendrix.com and then install the wordpress into that subdomain? Because, I really only want the them on my portfolio section.
I wouldn’t, but that is only based on if you asked me to guess your portfolio url, I would guess simeonhendrix.com/portfolio
I also don’t like WP’s default files in the main folder, in this case /portfolio/, so I would actually install them into /portfolio/cms/ and then move a few files by doing http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory#Using_a_pre-existing_subdirectory_install to push WordPress to the /portfolio/ by default without actually having the files lumped in there, totally personal preference. This becomes more of an issue in the root of a domain, not a folder like /portfolio/ but I would still do it. ;P