I did most of the install except the main electrical box. I ran all the lines and connected them to the units, but I had @losetoa6 stop over and connect to the breaker box. Then I had an HVAC friend stop by and check all my work at startup.
I had a manual Tacoma for 15 years and went to automatic four years ago, and the only time I miss manual is 4WD mode in snow and hills.
Unfortunately, that isn’t very often recently.