Remodelling

I saw remodelling mentioned in another post.Is it easy or difficult?We just bought a new 4 berth Coachman last year and love it.We also foster and have 2 children extra at the moment,we use our awning when abroad for extra sleeping room.We are now considering another 2 children and wonder about converting bathroom to bunk beds.We are another weird lot that use neither shower or toilet finding camp facilities much better.Any thoughts appreciated.