"Brian" wrote

Any suggestions for removing these stumps or at least killing
them would be greatly appreciated.

Roundup, painted full strength on the new green leaves with a brush will
kill the stumps. To speed things up, wait a day after treating the leaves,
then cut the green branches and paint additional Roundup on the fresh live
wood.

Getting rid of stumps this close to a structure is one of your ultimate
landscaping challenges. If you feel energetic you could try digging around
them on the side away from the building and cutting the wood away with any
one of a variety of power tools. One of those rotary cutters would be slow
but safe, as would a power drill with a wide wood-cutting bit. But roots
that have grown under the building would be a real problem. Fortunately
roots do not seek out dry areas so if the structure was there before the
plant that may not be a problem.

Good luck.