Yes, switching is possible possible because you haven't entered any content yet.
However, I believe your guide could be integrated nicely into our general guide. Web publishing option A (integration) has a number of advantages. Please see here: http://www.guidegecko.com/help-publish2#web-publishing
You may want to reconsider to switch back to option A?
Do let me know your final decision (just reply here), and we will change it for you. Note: we can only change this BEFORE you enter your content.