Migration from Solr 4.7.1 to SolrCloud 5.1

[shacky]

Hi.
I have an old index running on a standalone Solr 4.7.1 and I have to
migrate its index to my new SolrCloud 5.1 installation.
I'm looking for some way to do this but I'm a little confused.
Could you help me please?
Thank you very much!
Bye