How could I make the same adjustment/rotation for every keyframe?

Hey everyone. I'm attempting to use UMotion to fix some character 8-directional strafing animations. So, for example, I have a "walk forward" animation, that I want to turn into a "walk forward-left" animation or "walk 45 degrees left." So, I used Unity's built in animation settings in the inspector to rotate the entire animation 45 degrees to the left. Then, in UMotion, I'm trying to rotate only the torso and everything upwards 45 degrees back to the right. I can do this with the Muscle group sliders, but only for one keyframe at a time. Or, select one of the torso bones, and rotate it... but again, only one keyframe at a time. Because the muscle group slider is only a drag slider (not on the number precise) I can't copy and paste from one keyframe to the next. Does this make sense, what I'm attempting to do? And does anyone know a good work around for this? 

PS: I think this type of thing (creating a 45 degree, walk left-forward, animation from a basic walk forward animation, would make a very useful video tutorial for other users.)