I've been putting up with a slow leak in one of the rear tyres of my Greenfield mower as long as I've had it. It would stay pumped up for about a day, but I'd need to have a pump on hand for next time I wanted to do some mowing. I had tried to remove the wheel so I could take it to the local garage and have him do the tube, but as reported elsewhere in the forums the aluminium hub of the wheel is corroded solidly onto the steel axle, and I'd already taken a chunk out of the hub when trying to use a puller.
So, with other repairs going on I decided to tackle the tube problem. First step was to remove the tyre. I remembered that the essence of removing tyres was to get the beads of the tyre into the gully in the middle of the hub, so that the far side of the bead had enough play to be pulled over the lip half way around the wheel. But, these are broad and tough tyres, so with the back of the mower jacked up and the tube deflated I enlisted the aid of some bar clamps to pull the tyre beads into the centre of the hub and keep them there. With the beads held into the gully of the hub it was relatively straightforward to use tyre levers (aka screwdrivers) to start wrangling the outer bead tyre over the edge of the lip of the hub. It was pretty easy to start with but got a bit tight about half way around, but the outer bead eventually came free of the hub.
After that it took some wrangling to retrieve the deflated tube from within the tyre, but it came out cleanly. With the tube out of the way it was relatively straightforward to get the back bead of the tyre over the front hub lip to get it all the way off. Not necessary, but it seemed like a minor triumph after so long putting up with the problem.
With the tube out and a bit of air back in it the leak was evident - a scratch line that ended in a puncture. There was nothing in the tyre tread to show a cause, a mystery. I had some tube patches and so they went on in short order and the tube then held air pressure.
With the tube deflated again it was just a matter of wrangling the inner bead of the tyre back onto the hub, inserting the tube into the tyre and then getting the outer bead back over the hub, using the bar clamps to keep the bead in the centre of the hub again.