Epson EISA Desktop - Manual (Page 89)

Position each SIMM so its notched edge is toward the back of
the computer; then insert it in the socket at an angle as
shown below.
3. Gently press down on the SIMM and, at the same time, press
the top to the left until it is vertical and clicks into place
between the metal tabs and the retaining posts.
5-14 Installing and Removing Options