Dispelling the spell with dispel magic would be the most straight forward way to eliminate the illusion, but it also eliminates the original text.
Should the spell be dispelled, the original script and the illusion both disappear.
However, an antimagic field only suspends the spell's effects (not dispels them) and this should reveal the text without invoking the deletion clause.
This is not a terribly convenient option for most parties as it requires the use of an 8th level slot or access to a natural area of antimagic.
Eyes of the Rune Keeper probably won't work
A warlock with Eyes of the Rune Keeper can "read all writing" but that most likely won't work here. The spell specifically says:
To all others, the writing appears as if it were written in an unknown or magical script that is unintelligible.
Specifically the text has an illusion on the text that changes it to be explicitly unintelligible. Unless you can see the original text (you can't because it is covered by an illusion) then you aren't able to read the original text.
However there is certainly some ambiguity here and thus a DM would be well within RAW to allow this if they choose to interpret it that way.