If you stay at RPH (or PBH, HRH), you receive the free unlimited ep for all guests on your reservation.
The free ep is tied into your hotel, not tickets.
Buy your discounted park tickets anywhere
Price out the difference from a package which includes hotel and park tickets to hotel and tickets from a discount broker.
Packages have a fees for making changes after it has been booked.
You didn't ask but thought I would add this:
All the hotels on the UO property are allowed early entrance to one designated park each morning.
You can do rides in specific areas one hour prior to official park openings.