Epson 386SX - Manual (Page 163)

If the jumper setting is incorrect, move it to the correct setting.
You do not have to remove the SIMM card to change the
jumper setting.
Replacing option cards
To replace any option cards you may have removed to access
the main system board, reinstall the card in the appropriate slot
and secure it to the back of the computer with the retaining
screw.
Removing an Option Card
If you later need to remove an option card, simply reverse the
steps you followed to install it. Remove the screw securing the
card to the back of the computer and pull the card straight up
and out of the slot. Then carefully wrap the card, preferably
with the original packing materials, and place it inside its box
for safe storage. Cover the end of the empty option slot with the
original metal cover and secure it with the retaining screw.
Installing Options 5-21