What screwdriver do I need to open a Steam Deck?
Phillips #0 or Phillips #1?
Simple question, complicated answer. The iFixit Teardown found that you need a Phillips #1 (aka PH1) for the back cover screws and a Phillips #0 (PH0) for the internal screws. However, there is much debate! Look at the comments on Step 2 of all Steam Deck guides.
iFixit added this disclaimer:
How do I take apart my Steam Deck?
As quoted from the Teardown, "remove eight Phillips screws, pry apart some plastic clips, and … that’s it, you’re inside—no messy adhesives, no exotic screws"
What other tools will I need to use to get inside my Steam Deck?
Opening picks are incredibly useful for prying open displays and devices. You'll need these to unclip the back cover and slice the adhesive that holds the screen.
What other tools will I want to use to upgrade my Steam Deck's SSD?
Luckily, though devices may try to trick us with small, hard-to-reach parts, tweezers work wonders at removing small parts, like foil and stickers. Use a pair of precision tweezers to cleanly remove the ESD shielding protecting the Steam Deck's SSD when replacing it.
Additional tools to replace the Steam Deck's screen
A spudger is a versatile tool perfect for safely disconnecting cables and locking flaps found throughout the Steam Deck.
The flat end can be used for prying and separating, while the pointed tip is good for poking and prodding. Since it's ESD-safe, you should be using a spudger as a prying tool around connectors and circuit boards, not a flathead screwdriver.
The iOpener is an insulated, heat-retaining bag that can be heated in a microwave and can be used to transfer heat to the adhesive that holds the Steam Deck's screen. This tool is the safest way to loosen the adhesive and avoid damaging the screen when replacing it. A hair dryer or heat gun may also be used, but be careful not to overheat the Steam Deck—displays and internal batteries are both susceptible to heat damage.
A suction handle is needed to create a gap between the display and the frame and allow an opening pick to cut the adhesive that holds the screen.
Additional tools to replace the Steam Deck's battery
The Steam Deck's battery is strongly adhered, requiring repeated heating and prying cycles. The heat produced by an iOpener may not be sufficient to loosen the adhesive, so a heat gun (or, alternatively, a hair dryer) is recommended when replacing the Steam Deck's battery. A heat gun can also be used to apply custom skins and wraps to the Steam Deck.
Plastic cards do a good job slicing the tough adhesive keeping the battery glued to the Steam Deck's frame.