Dell PowerEdge 2550 Rack Installation Instructions page 24

Pull the inner slides out to their fully extended position.
1
If your system has an optional bezel, remove it (see the system Installation and
2
Troubleshooting Guide for instructions).
CAUTION: Because of the size and weight of the system, never attempt to install
the system in the slide assemblies by yourself.
Lift the system into position.
3
F i g u r e 1 - 1 4 . I n s t a l l i n g t h e S y s t e m i n t h e R a c k ( F l u s h - M o u n t
C o n f i g u r a t i o n )
1-18 Rac k I n st allat io n G uide
slide release (green)
lift to release