To style components, you just copy the bootstrap CSS class(es) to a new CSS file (BSS conveniently makes a starter stylesheet called styles.css) and then you can override or change any of the stock Bootstrap CSS by writing your own rules (or creating them with the visual tools.)
Locked components cannot be unlocked. You can, however, convert them to HTML, and edit the code directly.
We unlocked some components in our last few releases. For the rest, the only way to modify them is to edit their options in the sidebar, or to convert them to Custom Code. Locking is necessary so that drag and drop can work.
I have the problem that I have a complete design import and now the title tag is locked. it is also not changed via the general setting. can i do something about this?