1996 protege AC leak

1996 protege started leaking freon. Added a can of freon with the yellow dye but cant see anywhere that theres a leak. Been about a week. Looked at all lines and found nothing. I know that there are 2 lines running into dash..Took glove box out to gain accedss underdash and took 2 nuts off black AC box to loosen . Loosened it but didnt take it off. Question...what else needs to come off to gain access to have a look to see if leak is in dash under black box???