It depends on the guard, whether it is annealed, and what re-shaping is needed. Is there a reason the triggers cannot be modified?
Bending the bow, which is what you’re considering, is tricky without generating twists or changing the angles of the front and rear extensions on a musket or fowling gun guard. Same with the handrail on a rifle guard. I recommend using a 2x4 as a help to keep it all straight. Make cuts in the2x4 which is on edge with a bandsaw, coping saw, etc to allow support of the front and rear extensions at the correct angles to each other. Saw out a pocket for the bow, with the desired final shape. Use wooden punches (sized to fit) struck by a hammer to move things as you wish.
Or if you’re good and careful freehand it. Either way be sure to correct for slant or ruined alignment of the centers of the front and rear extensions.