How do I mark the sale of an asset and close out?

Step 1: Enter the sale value as the current value of the asset. This will show the updated IRR.

Step 2: Archive the row. Make sure the sale amount is reflecting in your bank account balance on the same day you archive the asset row.

If you are archiving the row few days later, make sure you have an entry in the Asset Details > Value table > for the date the money came to your bank account. Set value as zero. Essentially you are saying even though you are removing the row today, it became zero value on the day the money hit your bank account.

Summary

The asset you owned till now, is now gone from your portfolio, and the money you sold it for is now reflected in your bank account or cash balance.

Don't worry, even if a row is archived, its history will continue to reflect in your net worth. So you won't mess up your Net Worth chart.