It depends on the trigger. Some triggers are installed using a retaining pin and some are not. Consult your owner’s manual or contact the manufacturer of the trigger for installation instructions.
Generally, you will need to remove the stock, upper receiver, barrel, and bolt carrier group from the rifle. Once these parts are removed, you will be able to see the trigger assembly and can proceed with installation.
Again, consult your owner’s manual or contact the manufacturer for specific instructions.
Mike Seeklander Answered question September 7, 2022