The overlay has been in place since May 2019.
Disneyland’s Space Mountain (SM) will be closing on the 7th January, 2020 for the removal of the Star Wars overlay.
According to The Orange County Register, the iconic attraction will only be closed for a few days during the switch back to the classic SM theming.
You can watch the Star Wars overlay of Disneyland’s SM in full below.
Source: The Orange County Register