@Zack Stevens In reference to the REPC, this is the most relevant section:
10.3 Condition of Property/Seller Acknowledgements. Seller acknowledges and agrees that in reference to the physical condition of the Property, Seller agrees to: (a) disclose in writing to Buyer defects in the Property known to Seller that materially affect the value of the Property that cannot be discovered by a reasonable inspection by an ordinary prudent Buyer; (b) carefully review, complete, and provide to Buyer a written Seller property condition disclosure as stated in Section 7(a); (c) deliver the Property to Buyer in substantially the same general condition as it was on the date of Acceptance, as defined in Section 23, ordinary wear and tear excepted; (d) deliver the Property to Buyer in broom-clean condition and free of debris and personal belongings; and (e) repair any Seller or tenant moving-related damage to the Property at Seller's expense. The provisions of Section 10.3 shall survive Closing
If you used a real estate agent, I would contact them and give them 24 hours to remove the property. I would also make it clear that you plan on disposing of the property after 24 hours if they have not removed them and they will no longer be able to recover the items after that time.