I feel like this question gets posed a lot in different ways and was curious if it might be possible to formulate it narrowly enough to get answered here.
For the most part I think the answer is determined by the question -- in other words, you find someone who does understand and get them to explain it to you.
Of course even with a pair -- or ideally a mentor -- one still must tackle a text in isolation. The "someone who understands" is finally the author themselves.
How to prepare yourself to evaluate and interpret a philosophical text? I'm looking for a strategic vision here.
Beyond tactical things like reading secondary sources or finding a pair/mentor to study with; and even beyond spiritual qualities (a certain patience, caution, charity, &c). Although ideally strategies for evaluation/interpretation will have an impact on the tactics and spirit of a reading.
What long-term sort of critical practices can help support the structured, rigorous reading and evaluation of philosophical texts?