Can pick up dead enemy with space bar, but can not drop it with same key. How can I drop the body?

OICW assault weapon. Mouse button 2 and wheel I use for scope. Not having a third button how can I use the granade launcher with this weapon?
Grateful for any help
Gabi

Using the OICW (Objective Individual Combat Weapon)

Default Keys:

Alternate Attack = Mouse 3 (middle mouse button)  
Firing Mode = \
Weapon Special 1 = Minus (near the Backspace key)
Weapon Special 2 = Plus (next to the Backspace key)
Weapon Special 3 = Left Bracket
Weapon Special 4 = Right Bracket

these are default keys.........

So how do you pick up a body in the first place? Example, in The Armory where you have to carry Sam to the Ambulance??

Use key,
in the armory it can be tricky, je35amove position till u can pick him up,

What do you mean by "use key?"

the use key... the key u use to interact wit hthe world eg open doors, pick locks, pick up bodies etc default is space.

Thank you for clarifying