For one, don't. eps files are vector images, whereas jpg are raster images - they're completely different formats with a completely different basis.
In general, I would advice to store all your images as pdfs - that way the vector properties are preserved for vector images, and raster images such as jpeg are embedded. You may need to install an additional package for pdf images (graphicx I believe), but it's well worth it.
Tricky question and answers here as some journals demand .eps files. If you can't save your native figure file as an .eps file there are some options. You can open your .jpg in Photoshop and save it as an .eps file. When you reopen the .eps file in Photoshop it looks good.
You can also use an online file converter such as as https://image.online-convert.com (lots of configurable options including color), or choose from many others. However, the online converters produce a file twice as large as the Photoshop option at 600 dpi. Original .jpg 2.2 Mb, Photoshop .eps 48 Mb, online .eps 76 Mb.