You basically have three options (and variations there of). Which method you choose depends on what the content of your html is, and what type of output that you want. Most likely, you'll use either method #1 or #3.
1) Remove Tags using a regular expression (Quick and Dirty) (Kevin's Suggestion #1)
Perl FAQ 9 - Removing HTML from String
2) HTML Parser - By tag parsing of html (Complicated and Verbose) (Kevin's Suggestion #2)
cpan HTML::Parser
3) HTML::FormatText - Generic Parsing of HTML to Plain Text
cpan HTML::FormatText