Use the wet method, just like you did with car models years ago. VeloCals makes some premixed application fluid that works quite well on vinyl stickers. I’ve also made up my own, using 3Ms guide for wet method application. Doing it this way is similar to applying water slide decals, except you peel off the backing, then liberally coat the decal with the wetting fluid, also liberally coat the surface you are applying it to, this allows you to move the decal around till you get it just right. Then pat it dry with a towel to remove the moisture. This method worked really well on a Gitane Defi I restored for a friend, those decals were huge, no way you could have just stuck those on, and got it right!
Tim