HP 3150 EN - Manual (Page 91)

EN Covers 89
7 Insert the small flatblade screwdriver into the openings (callout 1)
at the top of the back cover to pop the upper corners.
Figure 17. Back cover removal (2 of 2)
8 Remove the back cover by grabbing it on both sides and pulling it
away.
To reinstall
After placing the back cover in its correct position, squeeze the back
cover and the paper input tray together to secure the back cover.
2 1