I found this little screwdriver to be very useful:
http://www.homedepot.com/p/Ryobi-TEK4-4-Volt-Screwdriver-HP53LK/202351930
Use a new small Phillips bit and put the screws in a magnetic tray!

Those of you with the early versions stapled to the top have my sympathy.
You need a pneumatic stapler or might just want to remove the top and work
with it on sawhorses.

The three window version is the best mod you can make to your Westy IMHO.

Stuart