In the transportation guide on the official website of Tokyo Disneyland, there are detailed bus routes from Narita Airport to the park, which are posted here for you.
Tokyo Disney official website: http://www.tokyodisneyresort.jp/sc/access/
I checked it for you from the transfer information. The most recommended route is Like this:
Take the direct shuttle bus from Narita Airport Terminal 1, which costs 1,600 yen and takes 1 hour and 8 minutes to reach the Paradise Hotel. As shown below: