How to acquire a profound knowledge of your subject (4,6)

'how' is the definition.
Both the definition and answer are adverbs.
Perhaps there's an association between them I don't understand?

'a profound knowledge of your subject' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
'profound' could be 'deep' (synonyms) and 'deep' is present in the answer.
The remaining letters 'redly' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

'to acquire' is the link.

Can you help me to learn more?