Willard isn't directly accessible from Rt. 50. You have two primary options from the parkway:
(1) You can go west on I-66 and the take the exit to Rt. 28 North. Willard is the second interchange once on Rt. 28.
(2) Take the Rt. 50 West exit, as already mentioned. After a few miles, you can turn left on Walney Rd., or Rt. 28 South. I guess you could also go to Lee Rd. or Stonecroft Blvd. to get to Willard. All of those are left turns coming off of Rt. 50 West.