I've done plenty of door carriers. I can't say much that others haven't said but here are some tips that I can offer.

Re-use the OEM dog-tip allen bolt that holds the lock cylinder (or wedge shaped pieces if it's not the driver's side door).

If you drop something in the door an extendable magnet will find it.

Some Nissan or other random clips will work in a pinch.

Do yourself a favor and remove enough of the vapor barrier to expose the larger bottom opening.

On an 85+ degree day, the vapor barrier adhesive becomes serviceable.

The $25 Amazon unit works equally as well as the not-so-cheap units.

Apply a little Mobil 1 or other synthetic oil to the pivot points of the carrier assembly. It gets exponentially smoother.

Always disconnect the battery. Always.

Always reconnect the airbag and switch pins before reconnecting the battery. Always.

When you reconnect the battery, start the car and cycle through central lock. That should "reset" the actuator if you depressed the rod while working.

If you have the /!\ illuminated triangle on the dash, rotate the steering wheel lock to lock.

If the carrier won't go in all the way, there may be a random piece of rubber in the top of the door that has to be pushed aside.

I'll add more if I can think of any...