Be VERY careful when moving the display and attached 2 cables. While they are reasonably protected it is easy to over stress these cables, resulting in tearing of the mini ribbon cable attached at the base. Move the screen the absolute minimum required to get to the battery.
So regarding the 1st Gen pencil’s battery dying, I have a Public Service Announcement.
I purchased the 1st Gen pencil about 2-3 years ago when we got a new iPad, misplaced it for nearly a year until the last week (Oct 2020). Obviously the Pencil had discharged and seems to have lost all capacity to charge. Apple’s Support page clearly states for Battery Replacement (Pencil replacement in reality) the cost is $29 for Out of Warranty. For any other reason, the cost is $79. Apple Support acknowledged this, but here’s the kicker. You have to send the Pencil in. IF Apple finds that indeed its only the battery, then its $29, BUT if they find something else its $79… the customer gets no say. Once you send it in you are authorizing a charge of up to $79, Apple doesn’t email you to ask if you just want to discard it if its over $29… they just bill you with no recourse (no refunds, no partials). What a horrible way to treat your customers.
So beware of Apple’s Pencil, my recommendation buy something else.
Your iFixit shipping box is a great size for this
Long screw left side, short screw right side
small screw on left, big on right (connector on bottom)