converting a colored vector eps to coloring page single line art

I am very new to illustrator (or design at least).. I am not sure if there is an easy way to do this. I have several colored vector eps files that I would like to convert them to black and white images for coloring. I already know how to take off all the colors as you see in the image below... however, my problem is mainly 2 things:

• the double lines that show at the edges of the image characters:

http://ift.tt/1GIkVew

• the places where there was a gradient color in the image:

http://ift.tt/1wMTujJ

I know one can go over all the paths and objects and edit them in illustrator to make it work, but I have a lot of images to go over and this will be too much time consuming...

So,, is there please an easy to do way?

It might be very easy.. but I am very new with no graphic design background. I tried to search online, but was un able to find what shall I do.. may be because I did not know what graphic or illustrator terms to search for.. so a guidance of what shall i search for will also be appreciated..

What I need is for example to have this vector converted as this:

and not as this:

Thanks