Retrieving data from an old harddrive

Hi everyone.

I changed the HDD in my girlfriends macbook pro about a year ago, but kept the old HDD in case we needed it. It turns out a lot of our photos are on that HDD. I thought I had copied them to my external HDD, but alas.

So my question is this:

How can I retrieve data from that HDD without exchanging it with the current one in the computer?

Can I put it in an enclosure and through that boot from it?

All help is appreciated

Kind regards