I just removed the parts of a cheap chain tool that were in the way.They break off quite easily.
One of those removed parts is for lining up the chain tool pin with the chain rivet. The other is for loosening the tight link after pushing the rivet back in.
With those parts missing, a little more care must be used to line up the pin with the rivet. The tight link can be loosened by placing your thumb on the tight link, and flexing the chain sideways.
Be careful to not push the pin all the way out, but rather leave the pin slightly protruding on the inside of the side plate. That way when you put the ends of the chain back together the protruding pin will hold the ends together, making it easier to push the pin back in.