I don't have specific knowledge of that switch attachment, but most welded plastic parts can be removed and re-attached. It isn't pretty when you are done, but it does work, and the ugliness is completely hidden, so really doesn't matter.
The "welding" is originally done by melting a post that is molded into one part to flare it out in the hole of the mating part. Removing it involves drilling and/or cutting the melted plastic out of the hole. Re-attaching is done using a soldering iron or better yet, a ski repair tool, and some scrap ABS to fuse a new cap on the post. You can also glue them back together, but I generally prefer re-welding.
VIN 00252 2.4 Manual Midnight Blue
2008 Redline Manual Carbon Flash