How to invert a rotation axis?

Hello, im new in unity so please don't flame :)

I want to animate my AK-47 for my FPS game. In the scene i can set the rotation to a minus, (For example -2 will make it face upwards like it would if it had recoil)However in the animator if i put -2 it will automatically make it 358 degrees which means it is making a circle. I dont want that so is there a way to invert the X axis so upwards is + (Positive) degrees and the downwards rotation is - (Negative)?

For other models it seems that it is already the way i want, but for some reason the model that i downloaded from the Asset Store is inverted :/

Also please dont post scripts. I am not good in programming yet and i just work with Unity's tools. Not this "fancy" lines of code :P