I forget which end of the crossover board you need to access. Was it towards the top or bottom of the array? I forget. Sorry. Remove the top or bottom midrange driver and take a quick look. Can you access the solder points without removing the board? Possibly if partially behind one of the midrange drivers. I think it is possible, but you will need surgeon like skills 😊
The board is hot glued and can be pried lose by using a stiff paint scraper etc...between the board and cabinet and slowly and carefully separating it from the cab from the lower midrange driver opening. The driver wires have some slack and you can now carefully move the board within the speaker and position it so you can access the resistor solder points through a mid driver cutout. Solder in the resistor and reapply some glue, liquid nails etc. behind the board and press back into position. Not easy, but it can be done carefully.
The board is hot glued and can be pried lose by using a stiff paint scraper etc...between the board and cabinet and slowly and carefully separating it from the cab from the lower midrange driver opening. The driver wires have some slack and you can now carefully move the board within the speaker and position it so you can access the resistor solder points through a mid driver cutout. Solder in the resistor and reapply some glue, liquid nails etc. behind the board and press back into position. Not easy, but it can be done carefully.