Adding sugar to Island mist kits

I plan to add 4-5 lbs of sugar to my next Island mist kit (probably raspberry dragonfruit shiraz). I have read similar posts on this but was hoping for a bit more clarity on the exact process i need to take to end up with a 10-12% abv product. With these kits costing around $60 i would hate to screw a batch up.

Questions:

Is this as simple as just dissolving 5 lbs of sugar into boiling water, letting it cool then adding it to the primary fermenter along with all other ingredients listed in step one "primary fermentation?"

Also, what should my hydrometer read at this point if trying to reach 10-12%?

If i add 5lbs of sugar will i have to make any modification to the kit instructions before bottling? ie more yeast, longer wait periods etc...

I am new to wine making so any tips at all would be greatly appreciated!

I have made several of these kits (6) and added sugar. Personally I have not boiled with water but added the sugar straight to the bucket with the juice before pitching yeast. So far I have not had any issues.

I shoot for 1.090ish when I add sugar instead of using a specific amount. The sugar has a decent amount of volume, so I don't add as much water as the kit suggest. I usually aim for about an inch below the 6 gal mark. Then when I add the sugar - it works out about even.

The kits usually ferment very dry (0.990ish) which would be in the 13% range, but then you add the F pack which is going to change the final gravity.

I do let the time go longer especially on those kits where I add sugar. I keep the ferment on the cool side like when making beer so the ferment might not be as fast to begin with. Then adding a bunch more food for the yeast to consume will take longer than the kit instructions say. I usually have several things going at a time so it works out to when ever I get the time to work on a kit is when I work on it.

SG to 1.090 - 1.092 to start.

Sugar is sugar, doesn't really matter how it gets in there.

Thanks for the responses! They were very helpful. Hope to start this batch in the next couple of days.

I always add 1 Liter of Red Grape Concentrate with one pound of corn sugar so I don't lose the body of the wine. Friends and family absolutely love it. Another great aspect on the Island Mist kit is that its insanely good right out of the carboy.

Good Luck.