Probably is corrosion, so penetrating oil should solve the problem. Put it on and let it set for several hours and then reapply. Use a brass drift pin to drive the shaft out if you can find one so you won't hurt the threads on the shaft. Once you have the shaft out, you should be able to remove the brake assembly and slide out the wheel from the shaft drive. Don't forget the spacer on the left side of the wheel. Clean the shaft and lubricate well with lithium grease or some other good quality water resistant grease before reinstalling.