OK, here's what I did. The X-Acto knife to slice the backside of the plastic tubing. Clipped out the failed bulb. Soldered the new bulb to the remaining old-bulb-leads. The butane soldering iron is really handy for stuff like this.
Stuffed the wiring and newly soldered bulb back into the plastic tubing. Put the tubing back into the slot in the trim board. You can't tell the difference from one bulb to the next. The bulbs are 40 milliamp at 12VDC.
I got replacement bulbs from Premier RV in Junction City, OR. They were already soldered in strings to be threaded into new plastic tubing. Kind of pricey but I don't remember how much. Found some loose JKL 2174 bulbs at Mouser Electronics. Part number 560-2174. They are $3.36 per 10 and for this order they charged $4.99 for USPS First Class shipping. One caution - the loose JKL bulbs are physically larger than the originals and require a little dexterity to get back into the tubing.