Dell 2335DN - Manual (Page 272)

2.
Remove a new memory DIMM from its antistatic package. 3.
Holding the memory module by the edges, align the memory module on the slot at about a 30-degree
tilt. Ensure that the notches of the module and the grooves on the slot fit each other. 4.
Press the memory module into the slot with care until you hear a "click". 5.