You can file the I90 to renew a 10 yr GC within 6 months of the expiration. Now of course in the case of the OP they are looking to remove conditions via the I751 and not renew a valid 10 yr GC, so it is not relevant to them, but they certainly could have seen mention of the 6 month window.
To the OP, proceed as @Crazy Cat and @OldUser advised with the I751, do not file an I90, and do not follow any guidelines related to an I90 filing.
Good Luck!
You should file Form I-90 to renew your Permanent Resident Card if you were issued a card valid for 10 years that has either expired or will expire within the next 6 months.
https://www.uscis.gov/i-90