The worms , tiger worms/brandlings call them what you will , will move in after the initial heat up process .
If the pile is too dry , it will just sit there and do nowt . Too wet and it will do much the same , lol .
It just needs to be damp , and kept damp , and well mixed .
Horse manure will help get it going , try not to use manure from horses that have been wormed or are on other meds .
Adding compost from a previous heap will not really help get things going , as it is in a different stage of decomposition , it may , in fact , slow things down .
Manure and urine , is what is needed . Worms , as i said , move in later as things cool down .
You can do it just the wormery way . This way you start off with a layer of compost complete with worms .
You don't want this way to heat up , it will just cook the worms .
Just add a layer of damp composting material 3" or so deep , on top of the compost and worms .
The worms will eat their way through this food , how long this takes depends on how many worms , how big the area , how deep the food layer . When they are well through it , add another layer . Repeat as many times as you want .
The worms will be in the top 6" or so , the worm eggs , deeper in the bed .
To make a new bed , take of the top layer of food and put to one side .
Skim off 6"-9" of the next layer and place where you want the new bed , then put the food layer on top of this new bed .