Boyd scored 164 goals in 296 SPL games and is expected to do well in the Championship.
“The chairman has done well and the club has done well to get Kris,” he said.
“We know all about Kris and what he can do. Of course the fans are going to be excited.
“Kris is not a dribbler or a flamboyant player, but he is the type of footballer who can score lots of goals.
“We like what we see of Kris and we think he will fit in well here. The only point he wants to prove is to do well for his team-mates and manager and he will do that by working hard for the team.”