Okay, I went to Sears and asked for a crow claws tool without too much success. After 1/2 hour looking for the tool I found it. After seeing the tool I thought there is no way I can use it to remove this square bolts. Then I had an idea to buy one of this sockets that fits all. And with a lot of elbow grease, I finally got this two square bolts out. The maintenance book for the Onan generator states to remove the bolts every 50 hours, right.. the previous owner never did. By the way that is a very handy tool to have in the tool set. Thank you everyone for your suggestions.
This weekend is our last camping trip of the season (Yogi Bear in Luray, VA). After ending that trip I will be winterizing my camper and waiting until next year to go ahead and go camping again.