I just did it today actually. Go to 'Edit Profile.' You go through all your basic stuff, you can upload a new resume (I skipped this part), and on the last page there is an area where you can put plain text (cut and paste) additions to your resume. Seemed pretty easy. I didn't upload a new resume only because I was just adding one line, but if you have major changes for whatever reason maybe you would upload a new resume. I thought I read somewhere on this thread that there's a max number of resumes that you can have on there. I currently have two and can't figure out how to delete them if I wanted to.