How to set a new mesh for your character ,with the score ?

So I want to know how to change the mesh of my character to an other one ( modified version of the actual mesh) if I reach a precise amount of score ?
I think its not enough precise , but I want while playing , each time my game reach 25 , to change the mesh of my character

You have your score variable that increases during some collecting event, or upon killing an enemy or whatever. Make an additional function that checks that variable, if its >=25, run setSkeletalMesh on your mesh component in the character blueprint to whatever mesh it needs be. Make sure to call that function in at the end of the event/function that increases your score.