Removing a barrel is normally done with a barrel vise and an action wrench. You need the right wrench to keep from bending the action.
Sometimes a pair of wood blocks bored to clamp on the barrel and held in a heavy bench vise will do, sometimes it won't and you will have to have a real barrel vise to clamp tighter.
Replacing a barrel requires machining, one way or another.
The simplest of the over the counter replacement barrels from Brownell's are short chambered which means you have to have a reamer, headspace gauges, and some technique. There are measurement methods you can use to simplify the process, if you have the micrometers and gauges.
I don't think you can learn to rebarrel a rifle one question at a time on the net.
Get a print catalog from Brownell's, they have tools and books.