How can I remove a deleted users Metadata

Please Help! I have just about pulled all my hair out trying to figure this one out….

I added a facebook like/send button to my blog – that was great when liking a post or article… but when clicked on any of the pages it was appearing on facebook with the page authors name and Gravatar. This led to hours of trying different like button plugins but all with the same result.

I then decided to add a new admin user with the company name as the author and assigned the company logo as its gravatar. I then added all the pages again as the new user (deleted the old ones) – Hey presto – this seemed to work and when the like button was clicked I had a satisfactory result showing on facebook – HOWEVER – it doesnt seem to work for the homepage.

I have spent countless more hours scouring the support and codex and believe that I have to delete the original users metadata. There appears to be a page on this in the codex

http://codex.wordpress.org/Function_Reference/delete_user_meta

but I am still a novice and am not sure what code and where needs to be changed.

Please could someone out there offer some advice as I dont want to break the blog and all the hard work in getting it to were it is!!!!