Well, a good walker can walk from the N'EX platform to the hotel, but you may hope to take a taxi for a few minutes from near Miyamasuzaka-shita crossroads; a one-way taxi fare is estimated at around 500 yen per car per ride.
Probably the simplest way is to go up Miyamasu-zaka Slope then go down Aoyama Street, but that sounds not easy for travelers carrying some luggage.
(It is strongly recommended that you pack lightly: https://www.japan-guide.com/e/e2274.html
In Shibuya Station you see signs written in black letters on a yellow background.
You first get out to East Exit.
1. Your Narita Express train arrives at Track 3 of Shibuya Station, and you disembark.
2. Then you walk on the platform for a while in the direction of Central Gate,
and go up the escalator | elevator to the passenger bridge.
3. You cross the passnger bridge,
and go down the escalator | elevator near Central Gate to the platform of Track 2.
4. Then you walk a little, and go down the escalator for South Gate.
5. You turn around, pass through South Gate, turn to the right,
and walk on the pathway to East Exit.
6. Then you turn to the left,
and walk northward along Meiji-dori Avenue to near Miyamasuzaka-shita crossroads.
7. You catch a taxi.
Your walking route from South Gate of (JR) Shibuya Station is explained in English on the website of the hotel.
- Sakura Fleur Aoyama: Access without using stairs http://www.sakura-hotels.com/access2.html
Enjoy your trips!