Step 1: You need to locate your descriptions ‘content’ code… It will start with a <div id=”……”> and have {description} in it. (Locate this in your themes html code via customize > theme > use custom html).

Step 2: Copy and paste this code (CLICK HERE) into your theme code. I put mine underneath my {description}. The width will automatically adjust to fit your sidebar. You need to replace YOURBLOGURL with your actual tumblr username.

Step 3: You may notice that your ask box doesn’t show up whilst your in customize mode & that you have a big gap where it should be. Don’t panic, just press save & view your blog… VOILA it’s there.

(Source: mynameisflicktutorials)