Converting 18 volt AC to 12 volt DC power

I have four MTH Bombardier cars that I would like to convert the overhead lighting in. I purchased Micro-Mark’s LED Flexible light strip and it uses 12 volt DC, 1.2 amps per meter of length. I want to use 10 inch strips, which are 0.254% of a meter. Any ideas on how to do this? Your help would be most appreciated.

Here is a guy that did it for some PE Flyer cars.

https://ogrforum.ogaugerr.com/topic/d-i-y-led-strips-in-s-gauge-pe-cars