Well
what you could try is to remove the stump
and then bungie connect the roots you want removed to a car a pull em out
Or you can just plant farther away

Having gone through the process several times, if you really want to get rid of the roots, I'd suggest use of a hose and getting water gadget (link is to one like mine). Use a mattock (that's sturdy enough to do the job) to dig and chop around the circumference and then the water gun to wash dirt away from the roots while cutting back a section of root closer to the trunk each time; repeat and repeat and repeat. You'll eventually get to the point where the trunk and roots can be pulled away. It's Work, but effective and can be done a bit at a time.

To make a bed without moving the roots, figure out and build a high edging around the circumference. Now build a lasagna-style bed inside (over the trunk and root area) by using layers of newspaper, green stuff, and brown stuff (or even just paper and shredded leaves) until it is at least 18" high over the woody part. It will decompose down to about 4" to 6" over winter so next spring you will need to build it back up another 12", but you can plant directly into the lasagna -- most annuals really like it and seem to adjust happily as the lasagna decomposes. You may want to re-build it in fall as it usually takes a more than a year for the lasagna to decompose the trunk - if you keep the lasagna dampish especially in summer, it will work better.

Unless a high wind literally knocks over a tree and leaves a wall of roots sticking up in the air-the water gun is fastest in that situation; otherwise,lasagna is much much easier to do and gives you a superb soil while it's working.

Here is a link that might be useful: water-powered weeder

I suggest going to one of the big box stores and buy a tool called a digging bar. It is a heavy steel bar about an inch square or round with a chisel shaped head on one end that is about 4 inches wide. It will cut through the roots in no time, but watch your toes.

Ichabod

Here is a link that might be useful: Digging Bar

Read on a forum somewhere to use a reciprocating (Sawsall) saw to cut roots. Tried it and it works. Dirt didn't bother the blade.

Bob

looks like its the sazwall or digging bar

when some of the roots are over 6 inches thick, its gonna be a tough job

thanks all

Im with Arizona Bob, We used a jig saw but I imagine a skill saw will do the job too. hand tools are the way to go!