Quite difficult TBH. Not only the different spelling, but also that there were lots of different words than we use now for the same thing, and cases where the old word looked like a weird form of something of today but then turned out to be very different; and then all the linguistic embellishment. Instead of saying "x and y happened on date z" (as you would read in today's court transcripts), it would say "and so then it happened that, upon so many days after Easter, when the moon was full, also indicated as the year of the lord so and so and this month, that the horrible event of which we are talking about today too place, where first x was said by person bla", ... - on and on and on. I wonder how they got anything done those days.

If you're into this sort of thing (and know Dutch), a really fun read is "Een notabel boecxken van cokeryen", a Dutch cook book from around 1510. Annotated (translated) version available at http://www.dbnl.org/tekst/_not001nota01_01/_not001nota01_01.... . Illustrates the issues above very well.