Sure, you can sweeten the wine! When it's completely done, completely clear, and no longer throwing any lees at all after 60 days, then it's ready to stabilize and sweeten.
Once you have the wine ready, just rack it into a new carboy where you've already added 1 crushed campden tablet per gallon and 1/2 teaspoon potassium sorbate per gallon, dissolved in a little boiling water. I boil 1/4 cup of water in a microwave, then add the campden tablets and sorbate. Stir well, as it doesn't want to dissolve, and then pour that into the receiving carboy. Rack the wine into it, and let it sit three days (or longer- no rush).
After at least three days, sweeten the wine to taste. Use whatever you want- sugar, honey, grape juice, etc. The easiest way to do this is to pull out a sample of the wine and add your sweetener to taste. Do a couple of different samples, to see which you like best. When you find one you like, take the SG of that sample. Then, sweeten the whole batch just a tad bit under that Sg. For example, if you love it at 1.010, sweeten the batch to 1.008 as it gets sweeter tasting in the bottle.
You can dissolve sugar in some boiling water to make it easier to mix it with the wine.
Wait at least three days, with the airlock on, to make sure fermentation doesn't restart and the wine stays clear. Then you can bottle.