You'll need to use the open command.
Then you'll probably want to use a while loop to iterate through each line in your file.
Assuming that you are only interested in certain bits from each line (you didn't actually say which), you'll probably want to extract the bits of interest using a pattern match.
Finally, you might want to print your results.

That's pretty much it. Suggest you have a read of the docs for open, perlre and perhaps perlretut, then have a go at writing some code. If/when you get stuck, come back and show us what you've written and we'll be glad to help out :)

Cheers,
Darren :)