You're going to have to get the nose mounted solidly first. Get it lined up where you want it, then tape off everything you don't want to make a mess of. Yup, you guessed it! You've got some modifying to do! You can either do one of two things. You can either fill up the low spot with duraglass or bondo (which I don't recommend), or you can build that area up with fiberglass. You'll need a flat block, lots of sandpaper (at least 80 grit and 36 grit), masking tape, some poly sheeting (to tape around other areas so you don't use a whole log of masking tape), fiberglass mat, polystyrene or polyester resin, paint brushes, a fiberglass roller, and some patience.
After you get the nose mounted and lined up to the car where you want it, you'll want to tape off any areas you don't want scuffed up, or covered in resin. Scuff past the ares you want to build up. So in your case, scuff the area where the turn signal indent starts over to the edge of that pocket where your black out would sit. Cut pieces of fiberglass mat to fit the area you want to raise, but actually cut them smaller, gradually increasing in size until you get that area filled up to the point where you can use a thin glaze of bondo. You're going to roll the resin out of the glass, so this stuff will stretch out a bit. This is the part that is important because you don't want the mat completely saturated with resin, You're trying to squeeze out the excess and get all the air bubbles out of the layup you're making. Basically what you're doing is building up the low areas of the turn signal areas, but not overdoing it at each layup. Keep in mind that you want to build up the area lightly at each layup so you don't have a lot of sanding to do. Roll away from the bottom edge where the blackout sits. Work smarter, not harder.
So with that in mind, after your first buildup sets up solid, scuff up the are you glassed. You want the next layer to stick and bond to the last, and it you don't scuff between layers, you run the risk of delamination (layers separating). Use the block to sand with ALWAYS. Don't use your hand unless you want it all wavy.
Fiberglassing can be fun! You just have to take your time, don't get carried away with a lot of resin, and think two steps ahead of what you want to do in this case. You're trying to build up an area, not make a layup like you're creating a part. Sand what you want to cover, mask over what you don't want to cover, and try to keep the resin and glass away from the areas you taped off. Use the plastic to tape to the nose to aid in keeping resin off of places you don't want glassed or messy with resin. If you need help, just ask! I know reading this and deciphering what it says might be like reading Greek, but I hope this helps.