Replacing hose bibs for irrigation

Does anyone have advice for replacing hose bibs? From what I understand, to replace the existing hardware, it involves unscrewing the pipe, whose threads are inside of the house, just behind the siding.

I know someone who did this, and sure enough, the pipe broke on the inside and he had to cut away a chunk of the siding to repair the damage. Much fun.

The goal here is to modernize the hose bibs and allow for irrigation pipes to be attached.

Any ideas or experiences appreciated.

--Bob