The picture shows snow skids.
Considering two technicians working on the early type of skids for fitting it takes about 2 hours as helicopter has to be lifted up with 4 hydraulics yokes; 2,5 hours if also they have to perform fine adjustments.
Removal takes 1,5 hours.
There are some new skids allowing the helicopter to be rolled on them by pulling it with tractor without using lifting yokes and saving time, say taking 1 our manwork.
Maeroda