Compared to your option to use JRP from Haneda Airport,
you are now going to wake up earlier by two hours in the morning and pay about 1500 yen more,
in order to visit the Exchange Office in Odawara.
It sounds better for you to get your JRP in Shin-Yokohama Station.
The Exchange Office in Shin-Yokohama Station is the JR Ticket Office managed by JR-Central, which is open from 8:00.
http://www.japanrailpass.net/en/exchange.html450 yen | 448 yen (#) as a Keikyu fare.
Haneda Airport International Terminal Station
(around 6:30)
| Keikyu
Keikyu-Kamata Station
| Keikyu
(around 7:00)
Yokohama
: Please follow signs for JR lines; there is a Keikyu-JR transfer gate.
170 yen | 165 yen (#) as a JR fare.
Yokohama Station
(around 7:20)
| JR
Higashi-Kanagawa Station
| JR
(around 7:40)
Shin-Yokohama Station.
#: The latter price applies when an IC card is used to travel.
Shin-Yokohama Station
( 8:22)
| JR Tokaido Shinkansen: Hikari 463
(11:00)
Shin-Osaka Station.
- Map of (JR) Shin-Yokohama Station
http://english.jr-central.co.jp/info/station/_img/shin_yokohama_L.jpg: JR Yokohama Line is operated by JR-East.
: Your train arrives at Track 6.
: You first go up to the bridge then go down to the concourse,
pass through Yokohama Line North Ticket Gate,
turn to the right at the corner
and get to the JR Ticket Office managed by JR-Central,
which is near Shinkansen East Ticket Gate.
When you choose the Odawara option,
it seems you cannot catch a Shinkansen train (for Shin-Osaka) before 7:10,
so you wait for the 8:08 Hikari 503.
Odawara Station
( 8:08)
| JR Tokaido Shinkansen: Hikari 503
(10:26)
Shin-Osaka Station.