At 1040 i would be surprised if it has stopped, leave it a couple of days and check again.
You need to let it get down to 995 or a bit lower which will be dry then back sweeten after it has been stabilised.
Back-Sweetening from Moleys WOW guide.
As Iâve said before, a hydrometer takes out the guesswork. For a guide, 0.990 is dry, 0.995 is medium-dry, 1.000 is medium, 1.005 is medium-sweet and 1.010 is sweet. If you donât have a hydrometer yet, just take a sip. Your wine will be young and sharp with no finesse whatsoever but you should be able to tell where it falls on that range. To sweeten between each step requires about 2 oz or 60g of sugar, so from dry to medium needs 4 oz, 120g. Boil the sugar in a minimal amount of water, allow to cool, add it to your wine and shake gently. Alternatively, I prefer to just sweeten from dry to medium-dry, and would add about 250ml of white grape juice.