How do you put a inner tube in a bike?
To put an inner tube you should first remove the tire from the bike and deflate the tube. You should then separate the rim from the tire and twist the tube while inserting. You can get more tips by visiting http://www.davestravelpages.com/bicycle-maintenance/60-how-to-change-a-bicycle-inner-tube.html.
After you take the tire off and pull out the bad one.... put a little bit of air in the new one... it helps round it out to make it stay in the tire. Put it all back together THEN put the tire back on the bike.Hope this helps.