How hard or easy to swap out steven barrel?

Ok, so I have a Stevens in 243. I would love to have a bolt 308, to match my other rifle, ammo wise, 308 is cheaper and more available.
How hard is it to change out the barrel?

Thanks

EASY! They change out just like a Savage. (it is a Savage)
If you have never done one then start reading on how guys have changed theirs on this web site.
All you need is some very basic tools. One thing I would recommend is the use of Kroil oil, With the rifle standing up place a few drops of Kroil oil every few days in the front of the BBL. nut skirt is out over the BBL.
Kroil oil will help incase the bluing salts are acting like red lock tite making the nut difficult to break loose.
Swapping a BBL. on a Stevens/ Savage is simple. Have fun.
Send pictures of your build as it progresses...

It's as "hard" as you want to make it. The easiest way, get the right tool's, consisting of: action wrench,nut wrench,go-gauge. The folke's here on the forum pretty well posted me through it, look at the first post on this board titled "Head Space". It should help you quite a bit. Have fun, once you change a barrel, your hooked ;)

The last switch that I did was a full change over. I changed the bolt head, mag box and barrel in a little over 1/2 hr. I'm sure that there are guys on here faster than that.

And possum1 is right, save yourself the grief and buy the tools.

Great. Next question is where to go for a Savage/Stevens 308 take off barrel?

Check the vendor classifieds. Northland Shooter Supply usually has factory takeoffs at a really good price. For $12/year you get access to the member classifieds. There are often some good deals there.