Although cog says that if you can de-obfuscate, then the code is not properly obfuscated, I wouldn't say that. In the extreme, you can always ask perl to compile and dump the pseudo compiled code which should be... easy to read.
The low experience I had de-obfuscating code, I went down step by step. Take a line, start trying to understand it.
Try to find delimiters. Copy and paste small sections and try to compile them with perl, and see the result.
This can all be fun, but be careful. There is malicious obfustated code out there. Just take care whenever you use Perl to interpret a piece of code you don't understand.