AssemblyAngularVelocity works similarly to how AssemblyLinearVelocity in the sense that it is calculated based on physically driven BaseParts. Meaning the rotational speed of a part.
If you want to change the angle of a part you would have to change the angle of the part using:
CFrame.Angles()
If you want to rotate an angle by 75 degrees then your code would look something like this:
Part.CFrame = Part.CFrame * CFrame.Angles(0, math.rad(75), 0) --we convert degrees to radians since CFrame doesn't use degrees
Alternatively, if you’re trying to rotate a model your code would look something like this instead: