Yeah. Unfortunately, Bethesda in their infinite wisdom left out any kind of respec option. Only thing you can do is start over. Or practice the new skills, but then you'll still have wasted perks and stat boosts where you no longer want them.
Just start using an bow and put points into stamina. The wood elf in riverwood can be used to get free training up to archery 50. Don't mind the spent perks they help using enchanted weapons.
If that doesn't work, player.modav should. Difference is the number is how much you want or increase or decrease the value. Like player.modav magicka -20