That’s funny we are going with 5 this weekend versus our normal 10 or more for 4 cabins of stuff this weekend …
A lot depends on bottom content and water depth… we’ve tried some things in past like inter-tubes to float/move a huge lift through and over muck to deep water. We have and do use the boat to help pull stuff like long docks and lift’s out. That usually works best if you have wheels. Just be careful and go sloooow you can bend or break things pretty easily along with possibly hurting somebody if your not paying attention. We use rope not chains… 
In the end it’s usually just brute man force, lift and turn lift and pull. We do have some rope tied to some of our lifts to help lift which can help.
Taking things out at the end of the season we some pretty cool electric winch systems and at one cabin we use a 4-wheeler or truck.
Good News is after all is said and done it’s Fillet-Minion and cold brew.
Docks in/out is one of my favorite weekends! 