As someone who has made this transition, it's too long for this answer box. I did, however, make a website about it: http://webinarhow.to.
Briefly, in the long term, you've got to shift your mindset from a service model to a products model.
In the short term, you need to do more marketing, more blogging, more emailing, more partnerships. Work on getting a bigger list.
I've successfully moved from the clients/service model to the webinar/products model and if done properly, it's a much more reliable stream of income.
Are you looking to serve more people vs 1-1? If so webinars are a great format. In fact I think that often times group learning can be more powerful as many ask questions that others have but don't realize they had. So the learning is often times a greater experience in a group fashion.
What steps to take? Market to your audience your service and how it will be conducted via a webinar. Your fee for this type of training should be considerably lower and therefore appeal to your client base.
Hope that helps.
Webinars are a great way to teach and train in a group format. To expand your audience you may want to consider doing webinars as a lead generators and then move people into your funnel for paid group training. You will need to decide on a webinar service provider, create landing pages for registration and have an email list provider for following up, send info about replays and alerting your audience when you have more free and paid webinars. Hope this helps!