Create an income account called gain/loss on asset sales.
Calculate and post partial year depreciation (if this asset is subject to depreciation).

Then journal entries
debit accumulated depreciation and credit gain loss for the amount in the accumulated depreciation account (if this asset is subject to depreciation)

debit gain loss and credit the fixed asset account for the total in the fixed asset account

enter the payment for the sale as a deposit and use the gain loss account as the source account for the deposit