Cutting the speaker fabric to gain access to crossover

Lay speaker face down on a table or bench

Remove screws holding legs

Unscrew the 4 screws holding the terminal mounting plate

Feel with your finger where the opening for the crossover lies in the main frame of the speaker

Place 4 pieces of masking tape around the opening so that the inner edge of the masking tape is half of an inch from the opening.  You will use this inner edge as a guide for stapling the top edge and cutting the other three sides.

Use staples, tacks or nails to fasten the top inner edge of the fabric to the frame, using the top masking tape's lower edge as a guide

Use a sharp pair of scissors to cut a small hole in a bottom corner where the masking tape crosses ( 1/2 inch outside of the opening)

Cut the fabric upwards along the edge of the masking tape.  Repeat going side ways, and then the side next to the terminal opening.  You should now have a flap of grill fabric that is hinged at its top edge

Staple or tack the loose fabric to the frame on the bottom and sides, carefuly ensuring that the tension in the fabric is uniform

Cut apiece of board to fit over the opening and mount with screws