One of the nice things about staying in an Epcot-area resort is the ability to walk to both Epcot and Hollywood Studios. Boat transportation is available, but can be slower, require long waits for the next boat, and sometimes they fill up during busy times.
The trek between the parks is a brisk 15-minute walk. At Epcot, this path can be found by exiting the International Gateway (located near the UK pavilion), heading toward the Beach Club, then continuing toward the Swan/Dolphin, and then on to Hollywood Studios.
If you're at Hollywood Studios, you can take the path along the water which will lead you toward Epcot.
Not sure where to go or uncertain you're headed the right way? Just ask a Cast Member who will be able to point you in the right direction.
Learn about more paths you can take while at Disney World to save yourself some time.