Nowadays, there really is no way to clone a prehistoric animal encased in ice. If it could be done, someone would have done it by now.
As with bringing dinosaurs back, the only way, realistically, that it could work is rewriting the genes of a bird and turning the embryo into a dinosaur-like creature, but even this method can't be done nowadays; it would take probably 50 or so years and even then it's not a guaranteed possibility. Plus it would take even longer to get actual dinosaur species.
Cloning a previously living dinosaur is practically impossible by realistic means. DNA doesn't preserve well enough and you need all pieces of the puzzle to create a living dinosaur, or any animal.
Now if you want to go with sci-fi means, which aren't really plausible but can be written in a way to make it believable, one method would be to get blood from a dead mosquito as in Jurassic Park, or a time displacement as seen in Dino Crisis (switching an area of time with one from a different time, resulting in the area around the facility in the first game to be replaced with a jungle filled with dinosaurs).
But it would probably be a good idea to come up with your own idea, rather than directly copying either of these two ideas. Finding a creature frozen in ice and reviving it (as seen in the old cartoon Cro) is, in my opinion, overdone and wouldn't seem very original.