you do need the plastic cover... it snaps into the top and holds the unit in place. It is a little bit of a tight fit.... dont take the engine out.... you have to take the coupler cover off, have some extra length of wire added on the existing wire if you need it (and with heat shrink tubing on the connections if you have it... if not harbor freight)... seems like most people add a 10amp fuse in the line as well......
Then pop the two bolts off the midshaft housing and stick the bilge bracket on with the blue strainer already installed... then put bolts back in and pop the top part of the bilge on.... then send the wires up to the battery.... put some eyelet thingies on the ends of the wires and then hook up to battery.... good to go.