On Wed, 4 Feb 2009 05:37:06 -0800 (PST), stryped
wrote:

I have a trailer with 215/70/15 inch tires. Two of the tires
constantly goes flat over a period of about a week. I went to tractor
supply and bought a 14/15 passanger radial tire tube yesterday.

Is there a good way I can take this tire off at home and install the
tube and tire without a professional tire changer? I have done it on
the small 4.80 wheels, but nothing this big.

Ir is this impossible and I am asking for trouble?

It's not impossible, but a heck of a lot of work.
You need to break the beads - I've done a lot of them with a slide
hammer on the farm and doing "in the feild" equipment repair. I've
done it with a jack under a beam or heavy vehicle. Have done it with a
tractor loader, and by driving over them with a truch.

Then you need a pair of good tire irons to pry the bead off the rim,
and to put it back on after inserting the tube.

Generally a WHOLE LOT smarter to just take them to a tire shop or
general garage and have them done on the tire changer.