Attention: possibly a replacement of the transformer is necessary, because LEDs require 12V DC (DC). Halogen transformers, however, have often alternating current (AC). In addition, almost all halogen transformers have a minimum load. That is also the reason why all other fast also go after the precipitation of some halogen lamps broken. This minimum load is often not achieved with LEDs. Therefore urgently a LED transformer solllte be installed.
What happens if you do not, you can read at the 1-star reviews)