Hi HedgehogHappy
I’m not sure there is really anything you can do but wait until they vacate the premises and feel honoured that they have chosen your garden to nest in. It’s all part of having a wildlife friendly garden. Only thing is, wildlife doesn’t always stick to our rules! Bumble bees quite often nest in bird boxes and other box type locations. When I have had them here (not sure of the exact species) they vacated fairly quickly.
Perhaps you could consider getting/making another box for the hogs, in the meantime.
