remove

hey guys, so i picked up a motovert RX for road use (mainly for trolling my friends) unfortunately the previous owner had the batter in the wrong way round (blew the fuse) i replaced but seems the charging system isn't working, ie go for a ride and 15mins or so the lights are pretty dull...

I have a mini bike but I have no idea how to remove my front sprocket. I'm tinkering around because I'm new to this and mini bike currently is a pos haha I watch video but they all have a nut to remove to get the sprocket off. I don't see any nuts to remove.... Here's a photo

gday, guys and girls. im trying for the life of me to remove the bolts out of the old set of hubs, i cant seem to crack the bolts, i dont want to snap my allen key, or damadge the bolt heads them selves.... any ideas?