In Acrobat Pro X changing the font is a convoluted process, but with the new editing tools in Acrobat XI it's much simpler. However it won't get away from the fact you need the fonts installed on your computer before you can create content with them. Changing a font within a page will often cause problems because the character widths will be different. PDF editing is not word processing.
Look at the PDF's properties (CMD-D) and on the Fonts tab it'll list everything used in the file, so you can cross-check against your list of installed fonts and work out exactly which one you need to get hold of. Acrobat expects the typeface to be an exact match and doesn't create 'false' styles for bold or italics - for example it doesn't consider Helvetica the same as HelveticaNeue, even though they look the same on screen.