As "wanderer" said, you will have to remove the trigger pin, and in doing so, you will loosen up the sears, BEFORE you CCW twist the trigger guard.
If you turn the guard BEFORE you loosen the trigger, you will gouge the front of the trigger guard on the front of the trigger.
AND, BE CAREFUL when you remove the trigger pin, because when the sears drop down, there will be two sear return springs and plungers that like to launch themselves into space. Do this over a nice, WHITE sheet or the like, so you're not like me and end up on your hands and knees crawling around the shop looking for the re-entry vehicles.
Whiz