Can I cancel only the first half of the return ticket (Moscow-Amsterdam-Seattle)

Can I cancel only the first half of the return ticket (Moscow-Amsterdam-Seattle) on July 26 and use the return part of it (Seattle-Amsterdam-Moscow) on August 08? Will the ticket be valid if I inform the companies (DELTA and KLM) in advance? If I can, who should I contact? My flight confirmation is HI3PVJ.

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arealy   3 ���� ����� 17-07-2021T18:51:38

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