If you are comfortable with DIY, he is also correct in that it is not too difficult.
The needed tools come to $30 on sale as shown below.
The Tool I would (An oscillating multifunction tool)recommend is currently on Sale at Harbor Freight Tools for $19.99 and can be found on their site at the following URL: http://www.harborfreight.com/oscillating-multifunction-power-tool-68861-8493.html I buy from Harbor Freight All the time, and it looks like they have quite a store presence for you there in Phoenix such that you probably have a local store you can pop into to check out and save on any shipping charges.
The accessory that you will want is also available from them ($9.99 on sale) and can be seen at the following URL:
If you are on the fence about whether to purchase the tool - their is no rush. Harbor Freight puts that particular tool on sale probably every other week - so it gives you something to think about.
If you do decide to give it a shot, a vacuum cleaner running along side of the tool as it is cutting will keep the dust to a minimum.
And then a how-to video for regrouting....
Tim, it was a great idea starting this thread. I've appreciated it.