Easiest is a taxi.
Easiest that is cheapest is to take a bus to DHS and either walk or take a ferry over to the Beach Club, this is assuming you are talking breakfast (before parks open).
If it is a dinner, on an Epcot day you can exit Epcot through the International Gateway and either walk or take a ferry over to the Beach Club.
I can tell you the most difficult way from personal experience... that would be to listen to the service desk in your resort and believe any park bus will work, then take the one to MK and wait (at 6:30 am) for one to take your from MK to the Beach Club only to find out there is none that do that so you have to get lucky and have a bus driver take pity and stop (to let you know that none will be coming) and then he calls in and gets special permission to take you to the Beach Club.