Before fitting the new charging port look on the reverse side of the part for the ‘lego’ style connector. Be aware when refitting that this needs to fully click home to the main board.
Once the USB port is in place and the connector clicked home fit the single screw to the right.
Now check the tablet is charging (remember to wait for 10 to 15 seconds for the red light). If you don't get a light check the connector is fully engaged.
Once you are happy it is charging disconnect the micro USB cable and refit the plastic and the metal charging port retainer (2 screws).
Check it still charges okay, if so refit the back (the existing glue should be okay for normal use - however it is now obviously not got any water resistance )