The question is ... why?
If you are in the market for a new bike and want a triple, then buy a new bike with a triple surely?
If you change the components on the bike immediately you get it, you may possibly be messing up any warranty you may have.
If you think the Orbea is a good deal, and may still represent a good deal even including the cost of a change to a triple, then ask what the triple is for? Is it just to give a lower bottom gear? If so that could be acheived more cheaply by sticking a different cassette on, and possibly a long-cage rear mech?