Map Too Big

Hello,  Ment to set my map to 50x50 but instead put in 500 by 500 and now can't load my campaign.  Please help me to remove the offending map page. The campaign is princes of the apocalypse of which I am the creator.  Thank you. 

If the player flag is not on the map, you can create a dummy account, invite it and promote it to GM. The GM would come in on an alternate (flagged) page and could delete the offending page without loading it. Alternatively, if one of your players is willing, you could promote them and have them do the same thing. If that doesn't work, post back and I'll see if I can call a dev to come in and help.