export potoshop to a print-ready file, is it possible?

A bitmap file PREPARED CORRECTLY will work just as well as a vector file. A RIP can handle either (obviously you can print photographs, which are always bitmap artwork) and will print just fine. You need to find out if PDF/X is ok and get specific guidelines on formatting, printer's marks, bleeds, spot colors, and all of the other fun stuff required for a press.

Or just pay the printer to prepare your artwork for press.

I imagine a packaging design includes vector objects such as text. Vectors are treated differently to bitmap such as images. The printers RIP can process them - making a bitmap eventually, but without issues of poor quality sharp edges etc. 

I hope this helps
neil barstow, colourmanagement net :: adobe forum volunteer:: co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

@JAVIER5FC8 - You need to explain this to your printer. Good luck!

To preserve the vectors in your text, save the file as PDF. (That may be sufficient for you printer this time)

Next time, create the file in Illustrator or InDesign. Those programs are better-suited for packaging design. 

Any raster images you need can be processed in Photoshop and placed into your final layout. 

Sounds like he wants vector artwork. You can ask the printer if you can send them a png file. I do not believe there is a package in photoshop or illustrator.

You can recreate artwork in illustrator, turn type to outline. Then the printer should only need esp or pdf which ever they prefer to use.

Without  knowing how detailed the art is you might be able to make and expand. It will trace your artwork. But if it is complicated  you would better tracing it in your control.

It's a common misconception to believe Photoshop can be used for anything. It can't. It has some very clear limitations.

They probably want this design as a vector file. That's what Illustrator does. But Photoshop doesn't do vector - it's a pixel-based raster image editor.

So the question is how to salvage this. If you have specific dimensions and a reasonable resolution at that specific size, it may still work.

A print-ready file usually means a CMYK PDF, separated to the CMYK profile that corresponds to the actual print process. But it's hard to tell in this case. I think you just need to come clean with the printer and ask them what you should do.

Next time, do it in Illustrator.