Convert 50 DPI to 600 DPI PNG

I need a freelancer who can convert a 50 DPI file into a large 600 DPI PNG file without losing any resolution. The primary use for this file is printing, so it is crucial that the quality is top-notch.

Key Requirements:
- Convert the file to a 600 DPI PNG without degradation of quality
- Maintain the original colors, no color adjustments are needed