If you're in a rush or if you only need this trohpy and "Legend" (for slaying a legendary dragon) for 100% Skyrim completion, there's an easy level-up exploit. You'll need to have the Black Book "Filament and Filgree", something that you'll also need for the "Hidden Knowledge" achievemen". With such book in your hands, select the Secret of Sorcery from the three rewards offered inside the book. This will grant you a skill that can be activated once per in-game day that makes all spells cost nothing for 30 seconds.
Then you need to know the Adept level spell Telekinesis (there's always one book of Telekinesis in Redwater Den, near a corpse).
With Secret of Sorcery and Telekinesis, you will need to find two points on the map that are at extreme opposites from eachother and use them as your reference points. Once in one of them, make sure you have objects on the overworld that can have telekinesis casted on them (either drop them on the ground or find a spot with items on the outside like armor, weapons or even ingredients).
Cast Secret of Sorcery so Telekinesis costs nothing, then cast it inmediatly on an object so it floats, and then without releasing it, open the map and teleport to the other point on the other extreme of the map. If done correctly, your Alteration will go straight to 100, granting you the adequate levels. Make Alteration legendary, wait for an in-game day to transpire so Secret of sorcery refreshes and then, just rince and repeat until you've reached level 50. If you keep going to lvl 78, Legendary Dragons will start spawning, and this will allow you access to the other trophy I mentioned, "Legend".
With this method, the legendary dragon will prove quite tough, since you've only upgraded Alteration for quite a few levels, but it's a nice challenge. Hope this helps.