It's not too terrible, you need to undo the screws on the bottom, the nuts on the input & output jacks, then it should pull out most of the way. There's a ribbon cable that connects to the secondary board that has the pots on it, so full removal of the board is a pain, but you shouldn't have to take it completely out to do any mods. Not my photo, but I found this online:
EDIT: I should also mention that the solder on these pedals has a very high melting point - too much for most cheaper soldering irons. If you're having trouble getting the factory solder to melt just drop a blob of your own solder onto the pad that you're trying to melt. Let it harden, then apply heat again, the two solders will combine, lowering the melting point. Now you can easily remove the solder with your desoldering braid/solder sucker.