This Blueprint installs to slot 16 by default.

Before importing, remove all the original items that the default game allows (such as the outhouse etc but not items that a scrapper would, for example Longfellow's cabin). Also remove the bed in the cabin. The bed can be removed with disable and then markfordelete console commands, or with the extra objects option enabled in place everywhere, or a scrapping tool. Alternatively you can keep the bed and remove the beds and furniture that spawn around it with just the regular workshop mode. 

You will need to have installed Transfer Settlements (I used v1.93) and its pre-requisites: F4SE and HUDFramework.

The settlement has 32 beds, 53 water, 42 food, 200 power and 284 defence (8 from spotlights, and 12 from guards). This build also has chemistry, power armour, armour, weapon, cooking and nuka-mixer stations. As well as a terminal in the nuclear reactor room.

There are 20 jobs available. 
Tier 3 clinic, bar, general store, weapon seller, clothing store and armourer.
Booze Still. Soda fountain and hairdresser.
7 farmers. 2 guards.
2 Scavenger stations (one partly sunk into the guard tower base in the wall near the jail and one partly sunk into the mannequin/tentacles sculpture near the bus).

There are 5462 items to import. This may cause performance issues as there are so many and may cause a long import. 

There is a table lamp in the drug vending machine shack, it will not be lit once imported. To activate the lamp go into workshop mode, select then deselect it and it should now be working.

After import the settler beacon, traps and cages will all be on. The beacon is next to the huge tower. The traps, cages, fireworks and more can be controlled from switches in the shack overlooking the arena (the one beside the traffic  lights). 

There are cycle lights sunk into various lamps around the settlement. If you position yourself carefully you should be able to change their colours. There are 3 in the ceiling lamps in the soda fountain cafeteria, 1 in the drug vending machine shack, 1 in the general store from the ceiling, 1 in the bar (you may need to move the 2 junk items by this one), and one in the blue boxcar near the cafeteria.

Finally 3 of the buildings (4 beds in total) are in the radiation area. This shouldn't affect vanilla play this is just something to be aware of.

The json file is just a list of objects and their locations and as such should not have issues importing.  If there are problems,  try selecting general settings, scroll down and choose PRESET: stable. This might help in some circumstances though the import will take longer, otherwise there is help in this excellent article or on the  transfer settlement mod page. I think there is also a discord server as well.

I did use Place Everywhere to make this build (though you don't need this) and I spawned some scrapable items using the console.