I have nearly 500 dgn files with different levels, different colors and different weights in all files but same levels are used in all dgn files can anyone help me to do with script or batch process or keyin im newbie please help me

I have nearly 500 dgn files with different levels ,different colors and different weights in all files but same levels are used in all dgn files can anyone help me to do with script or batch process or keyin im newbie please help me in points it would be very helpful and time consuming for me if anyone can help me in this i would be very thankful