You might want to check out
pdfreflow in the PDF forum. There is a GUI with installer for Windows, and for other platforms you get a java GUI (but no installer). It converts PDF to HTML, reflowing the paragraphs of text based PDF (though it doesn't support images). But it does normalize all the fonts, so they aren't so tiny.
Once you get a decent HTML document, you can use Calibre to create an epub or LRF.