1-First Make A New Email Id On Gmail or Yahoo
2- Then Go To Your Page Admin Roles and Add The New Email and Save It as Admin of Your Page! The Email will be added Automatically But Not will be on Screen ( Just Hidden ).
3- If Your Page Got Hacked or Someone Cheated You. You Completely Lose Your Access on Page then
What To do??
4- Go to the New Email Which Added as a Admin on Page.There should be Mail From Facebook About Invitation of That Page Which You added Accept It as Admin of Page, Then Make New Facebook Account with that Email and Go to Message there will be invitation open it and You are Now Admin on Your Page Again. Remove the Scamer/Cheater from Your Page and Add New Email Again For Security Reason Again Like this.