What is left is extremely easy. Or just bring it to a shop and pay for install.
Geissele triggers can be somewhat a pita to install but there are drop in triggers where you literally drop the trigger in and push the pins through.
Then install the safety.
You can also adjust the cylinder to line up with the detent while putting it in so you don't have to adjust the levers multiple times or if that way is easier just do that.
The Radian takedown pin is already installed and the detent/spring it is held in with a set screw so you don't have to do that step.
With a drop in trigger it should take you all of 5-10 minutes to put this together. There is YouTube and people here that can further help if you need it.